Iran will remain an Muslim country with Islamic laws and a democratically elected government.
In order for Iran to "remain" with a democratically elected government, it would first have to HAVE a democratically elected government. The point of the protests is that the government is not elected because the elections are rigged.
I don't see the point, really. Mousavi is no better than Ahmadinejad, in my opinion. It's ironic so many people are claiming Mousavi is the "Obama" of Iran, when Mousavi is actually more like the John McCain of Iran. He's been in Iran's political process before, and he was certainly no revolutionary then.
Mousavi was one of the pillars of the 1979 Iranian revolution and served as Prime Minister, a post now eliminated but then roughly corresponding to the presidency in Iran today, during Iran's war with Iraq, being generally credited with outstanding management of the economy and other domestic affairs during this time. Obama came to office with a record devoid of political accomplishments and has never in his life shown a willingness to stand on principle if it put him at any personal or professional risk, so I guess your point about Mousavi being no Obama is correct. Since I don't speak Farsi, I can't say whether Mousavi can read a speech as well as Obama can or not.
However, the issue is not Mousavi vs. Ahmadinejah or even Mousavi vs. the political structure in Iran, it is whether or not the presumptive leader of the free world will support the democratic rights of the Iranian people or not. It is impossible to understand why Obama has been so reluctant to voice strong support for these democratic rights since it is clear the US will be blamed for the protests regardless of what he says and since it is clear that the current regime will not yield anything with regard to its efforts to acquire nuclear weapons or its support of terrorism or its efforts to destabilize the governments of Lebanon and the Palestinians.