Inspired by this thread, I went and bought Puffin for my iPod Touch & iPad (and am tire-kicking the free Android versions of it and Skyfire on my Xoom, though Flash player still sort of works in the stock browser). For some reason, it never occurred to me to look for one: truly, I don't do a lot of mobile web browsing, so I have no particular requirement around Flash-enabled web sites.
However, based on my limited experiences so far, and even for as little mobile browsing as I do, it seems to me worth having a Flash supporting browser like Puffin around, even though it has some problems, 'just in case'. E.g., I can watch c-span video. it won't go full screen, and is not free of artifacts, but I'd rather have the capability than not. And there are 'Flash needed' sites that work much better than c-span for whatever reasons.
Convenience and availability often trump quality and productivity.