1st level in 4E is a pretty great tutorial level. Lets you learn how to play your class and build before the complications start to add up, and gives you a chance to play with your at-will powers before they become a consolation prize.
In the old 2E days, I don't think I ever saw past 5th level. 3E I only ever managed level 1.
In the 4E game I'm playing in, we've reached level 11, and are soon to hit level 12. In the 4E game I'm running, the PCs are about to hit 6th. Personally, since I only run a 5-hour game every other month, if somehow my current game breaks up, I'm starting the next campaign at whatever level this one ends, so I can experience the whole game and not get stuck in that restart cycle.