Thanks, fwho.
Even with the delay, it seems strange that this disparity in price can exist. With that price difference, if you were to buy bitcoins from BTC-e and then sell them on Mt.Gox, even with fees you'd still make about a 9.5% profit.
So what seems strange is that enough people aren't taking advantage of it to eliminate the disparity.
Some of us are
But not with BTC-e. For this to work, you need to buy form BTC-e, and it's damn near impossible to get USD to BTC-e without paying fees that make it not worth it.