In regards to the power issue, I actually lost a power supply which was working fine previously to making the trip to the LAN party. A staffer plugged me in, I went to fire up the box, got a light for a split second, and then nothing. Whether this was a function of it dying a natural death or something else, I have no idea; we went to Best Buy and got another one and that was that. I thought I'd throw it out there.
Second, I liked the improved Rock Band 2 tournament format. However, one thing that the change from a band selecting songs from the start to randomly chosen songs does is it puts the bands who go earlier at a huge disadvantage, compared to the bands who have time to go back to their computers and listen to songs a couple times to prepare. I can't help but think if there'd been even a half hour between when the songs for the round were announced and the first performance, the outcome might have been different, and the tournament as a whole more competitive and improved in quality.
The fans were a huge improvement; likewise the designated console area. The smaller tournaments were cool too, like the Home Run Derby and Smash Bros. I did wonder why there weren't actual trophies for them as they WERE announced tournaments, but we can't have everything we want I guess
Overall, a very positive and improved experience from last year, with room to improve even more next year!