Ok I finally have mine. I put 3-4 hours into pilotwings I like it, but it's not like it is a revolutionary departure from the SNES one or the N64 one so if you've played those just think of this a new missions, but the same philosophy.
We have already established that the launch line up is mediocre and everyone is pretty much just picking up the niche games that appeal to them at this point. (I did also pick up GR: Shadow Wars, but have yet to play it.)
I can't comment on the battery life as mine has always been plugged in. One thing I do want to emphasis, and I think Arkhan pointed this out earlier in the thread, but I couldn't find it at a glance.
There is a big emphasis on holding the system right to the point that you could be playing a game and you shift you wrist and then all of a sudden you are seeing double objects on the screen or burred vision, then you are shifting back and forth trying to get the picture to come in properly and not focusing on the game.
It is not a deal breaker by any means I'm excited to see what direction they go in terms of software, but the screen going into double vision at an inopportune time is going to frustrate a lot of people. I would hope it wouldn't be a problem once you got used to it, but who knows.