Sounds great on its surface, and while I absolutely believe in the inherent right of all people to defend their lives and freedom by any means available and necessary, this particular development could lead to some ugly consequences in the end. Everyone points to the Taliban as the poster children for a relatively small, ragtag, primitively armed citizen force backing down or defeating a First World, state of the art foreign army. While this is true to a limited extent, both the Taliban and Afghan civilian men, women and children have paid a very high price in lives lost to British, Soviet and American invaders, over the last century.
Similarly, if the average Ukraine civilian neighborhood or village arms themselves and goes out to meet regular Russian Army forces, they will suffer catastrophic casualties. That's not to say I myself wouldn't prefer to go down fighting if Pennsylvania was invaded tomorrow by foreign enemy forces—because I absolutely would rather fight and die on my feet rather than suffer on my knees in bondage. All I'm saying is that Russian military forces might target Ukrainian civilians they would have otherwise overlooked, had those civilians not decided to take potshots at them.