360's will always have the potential to RROD, just like PS3s and Wii's will have the potential to fail as well.
However, for the life of me, it seems like the absolute worst period is certainly over. The best place, I've found, to see how well the Falcon's are holding up, is to head over to NeoGAF, and read "my X360 died, and I lived to tell the story" - it has hundreds, if not thousands of RROD stories, and is about the biggest I know of. Unless something's changed in the past week, not a single person has claimed their Falcon has RRODed . In the same tracking time, a few Wiis and PS3s have died on their owners in the same timeframe.
So I'd tend to think that the reliability of the newer 360s is MUCH better than that of the older, pre-Falcon 360s.
So the biggest key, if you really can't get sleep at night, worrying about not having a console to play on, just make sure that if you buy a 360, buy one with a manufacturer date no earlier than October 2008, and confirm it's a Falcon by checking the huge Power Addapter (for lack of a better word), and check to see if it runs on 172-175 watts. The older, non-Falcons ran on 200+ watts. If you can confirm one or the other (preferably the later), you got a Falcon, and I'd say, chances are, something else would die on you before you'd get an RRoD.
Back from the dead, I'm afraid.