The main reason I was always skeptical of flash on mobile was because of the hardware on phones. That is the only limitation of it.
It's like trying to fit a desktop into a phone, there will be limitations that can't be fixed.
Samsung had announced they plan to have a 2.0ghz cpu out within some time, it will be mainstream by 2012. They also announced quad core mobile chips, I think Qualcomm will probably oversee that production. I see it that the bottleneck was trying to run flash on a slow cpu, like an old netbook.
There were too many architecture restrictions that slow it down. Once the hardware has improved, eventually flash can be supported easily, if not by third party.
As for the battery saves, well, can you save battery watching youtube all day on a netbook? I doubt it.
I'm still waiting for the day they will let us run our phones 100% completely by the AC, without battery support. This will fix the problem about battery drain with flash. Both android and apple are guilty of it, there is no way to run a phone completely off the charger only.