I just finished DMing a game last month that ended at 23. The only reason it went that far is I wanted to let my players have a few games with their epic destinies. Just way too much to keep track of at that level for me to have fun DMing it.
Lucky one of the other guys is a better Dm than me so they can get their epic fix.
The original campaign we started about 3 weeks after the first 4th ed books were released (shipping to Australia) would up a couple of months back after everybody reached level 30 and fought Orcus.
I played from 1st to 30th level as the same character without even a temporary death.