Already crowed market ? Thats funny. There is one option on the market, iPad. Everything else is vaporware.
I am willing to bet those alternatives suck, or pale in comparison. Maybe Google will get it right. Flash, is becoming irrelevant on these devices(as is much of the web thanks to Apps) and I can't see anyone coming close to the coolness of the iPad without blatantly copying it.
Sorry but its not just the hardware. The software and its efficiency will have a huge impact on the battery life. I agree, can't see it on Win 7.