Just set your alarm clock to beep at 4:40 just like I did. Funny fact, yesterday I did that for new splash (2:55) and I didn't remember it BEEP'd that loud. I woke up making a jump and shouted "Oh my god Diablo III". And then went on Blizzard.com and refreshed 2-3 times before it appeared. I starred at it like 15 minutes and went back to bed, lol.
I'm going to attempt to stay up until 3 tonight, and then go to sleep for about two and a half hours and have mine wake me up at 5:30.
argg i wish i could stay up... maybe il just wait till the morning... but argg it was so fun last time waiting for the sc2 announcement. but than if its WC Litch king release date, than i will be so pissed. o well, i think i wont be able to sleep any who.