Well my main concern is that my iPod Touch 2G's Battery is draining way to fast from the new mode they have for wifi (Wifi doesn't turn off while in sleep mode now) And apparently when i woke up to go to work my iPod was dead, and i always plug my iPod in my car before work. So that really bummed me out. And when i turned it back on it displayed a Green background, and it went away when i connected it to my PC. But still a bit strange. And besides that i read some other blogs and treads around the net and people have been saying ios4 is draining battery's, hopefully they will fix this in a update. Everything else in iso4 is fine.