I have a brand new MBP, 17", 2.3 Ghz, 8 Gig ram... and battery life is just awful—under 3 hours (overheating and lots of full throttle fan too). I called Apple, and they insist that it's a "bad battery." I think we all know here that's likely not the case. Anyway, they're sending a new MBP out. So be it. It's their dollar.
For my part, I would gladly roll back to Snow Leopard (the new machine comes with Lion, unfortunately). I really don't see Lion's new features as anything that new; kind of like the dock and desktop shuffled and re-dealt.
Perhaps worst of all is the instability of Lion. Adobe Premiere 5 is crashing, along with Motion 5 (a lot!); Final Cut Studio's utilities such as Cinema Tools won't even open; and I find overall that programs are opening slower. After two weeks of use, I guess I can say that Lion is really good at email. :-/
The release of Lion in its present condition is somewhat surprising. In the end, if this isn't fixed in two weeks, I'll just return the laptop and wait for Silicon Valley to glue itself back together.
The Apple has fallen pretty far from the tree this time around....