Now, for a bigger response to the OP, I think there's a couple of things you're missing in your assessment.
First off, with the technological advancements to manufacturing, less and less labor is in demand, granted. However, the only reason human labor in capitalist manufacturing is ever replaced by machine labor is if it simplifies the manufacturing process IN A PROFITABLE MANNER. What does this mean? Every technological advance in manufacturing makes the products cheaper to produce. Combine that aspect with basic anti-monopoly laws to ensure competition in every market and you end up with a trend of technology driving down prices. When everything costs less, less labor is required for each person's necessary upkeep. This is exactly the aspect of technology as it relates to capitalism that allowed the industrial revolution to increase our basic standards of living so drastically over such a relatively short period of time. This is one of the few things that I believe the Marxists got correct.
Where I begin to fork from the common opinion among that crowd is that I also believe that those advances in technology that sacrifice the need for human labor simply for convenience also further this end. ATM's, for instance (and I still say Obama was a jackass for trying to blame our economic woes on these), save everyone time that might otherwise be spent traveling to a bank. These little conveniences add up.
Between the time people no longer have to spend laboring to pay for their basic necessities because those necessities are increasingly easier to produce and, thus, increasingly cheaper (prices driven down by competition that can profit with less and less cost per unit), and the time people save through technologies making basic process like acquiring meals and groceries, banking, etc less time intensive, you end up with people who have more time. More of their labor time can be spent moving toward non-essentials once their needs are met, and they end up with more free time to kill in a standard 16 hour day (assuming we're all sleeping well and getting our solid 8). With more free time to kill, people need more stuff to do. . . hobbies and entertainment. This is why occupations like actor and professional athlete have become so lucrative in recent years when, through the VAST majority of human history, these sort of entertainer roles were hardly a path to significant economic prosperity. More free time creates demand for more non essentials. This is also why we live in a country that has a poverty line at which people can afford to live in an apartment with internet access, a flat screen, and a smart phone. If you honestly acknowledge what is and is not a human necessity and take a look back at the labor hours that once had to be dedicated to acquiring -just- those bare basics, it's pretty hard to make the argument that technology slowly chokes out the masses in a capitalist system.
Next, I won't argue particulars in the definitions with you, but I will argue that if various levels of regulation can all be called "capitalism", then our current down-turn isn't definitive proof that capitalism is doomed to failure. The argument can be made that our current regulatory, tax, and currency environment can account for a great deal of the stagnation of capital in the hands of the super rich that you've cited. Environmental regulations (some good, some bad in my opinion. . . different argument) have nearly frozen the development of natural resources in our country while we drain tax money from our own economy to help other countries engage in the sort of resource development that we've deemed unclean (Brazilian oil rigs, for instance). Without a strong domestic supply of the base materials that such development facilitates, manufacturing requires the import of base materials, which increases the cost of doing business in the US. We've got one of the highest corporate tax rates on the planet, last I heard. . . also makes it more expensive to do business here.
We're now setting the precedent that the government can force a company to suffer an economic disadvantage by not allowing it to allocate resources from state to state in favor of lower overhead. . . essentially, set the precedent that if whoever's currently in government decides that there's now a moral imperative that makes it justifiable to hamstring a corporation and prevent its economic expansion, they're gonna go ahead and use the force of the government to do that. Business people look at that as the sort of thing that increases the overall risk in doing business somewhere.
We've also set the precedent that, if the government decides your business is too big to go through the bankruptcy and restructuring process because you'll have to lay off too many people, then they can go ahead and take over and restructure it as -they- see fit. In the case of GM, that involved telling the bond holders to take a f'in hike. Now, in case you don't understand the bond holder concept, it goes like this. . . A company wants to expand to fill a larger portion of a perceived economic demand, so they sell these things called bonds. They work like the bonds the govt sells. You buy them at one price and, some predetermined amount of time down the road, that bond entitles you to a return on the investment, complete with a predetermined margin of profit. When the people buy the bonds, the company uses that influx of capital to expand (which in turn creates more jobs). This expansion, if the company is a successful one, also expands its profits. This expansion of profit enables it to pay back the bondholders down the road with that margin of profit, and then still profit itself. If, rather than allowing every company to go through the standard bankruptcy and restructuring process, the government can decide that it has a moral incentive to favor the employees universally over the investors and tell the bondholders to take a f'in hike and eat their losses, they create an entire new dimension of investment risk.
On top of that, there's now talk about potentially doubling the capital investment rate, which, like risk, would stifle investment. Less potential profit margin means less incentive to invest. More risk means less incentive to invest. Less incentive to invest means less investment. Less investment means less expansion and, thus, less jobs. Less investment also means that those people who are raking in the money have more incentive to sit on it and less incentive to spend it.
There's a couple of assumptions you can make about virtually all of the super rich. They want to use their money to make even more money and they're good at using their money to make more money. If they've stopped investing it's not because they wanted to have a Ducktales style money bin and swim around in a shitload of loose change. . . it's because they don't feel that the potential rewards of investment are worth the risk, and given their typical proficiency in such manners, it's safe to say that the opinions are, by en large, well informed. If the argument can be made that various aspects of government involvement in the economy are the cause of a good deal of the stagnation of wealth at the top, then its hard to say definitively that capitalism in all its degrees has failed.