On the cans, I'm seeing quite a bit of higher end stuff coming in cans. Of those I've tried, I'm not sure I could tell the difference between a can and a bottle. Honestly, I'd probably have an easier time telling the difference between Bud in a bottle or can versus a microbrew, and it could be, as noted, due to the type of cans used.
My preference is beer in bottles, but the Mr Beer brews I've been making have been going in the plastic bottles, and they've been coming out quite good.