Yeah, 4th ed is simpler than 3rd ed in many ways, but not for any ways that would count for the purposes of running a one-shot, I think. Setup/explanation time is still long. But like Enron mentions I was also thinking about the possibility that if everybody we think is coming to the con plays, we could have up to 8 players (!). Fights in 4th ed are a lot of fun but definitely not short.
Well, I just blew a ton of money. I spent my bonus money on a MacBook Pro. Yee-haw! Now I'll have to actually get my hands on a copy of Windows since this thing can actually run it... I predict this expensive piece of hardware will end up being mainly a Planescape: Torment and Thief II machine, and I'm fine with that!