edited a bit:

well by delaying the stats those who hop around might have to just end up picking a pool and sticking with it if the larger pools do it.
the smaller pools probably want the increased traffic so they can lower the variance and the hoppers can stick with smaller pools.
thus the larger pools enjoy more dedicated resources all the time then just at the beginning of rounds.
and the smaller pools can decrease their variance by being hospitable for pool hopping.
there is no proof that i can see that delaying stats for an hour causes a pool to lose users. just look at deepbit.
also the amount of mh/s hopping, based on what i see, is only 100-200 gh/s (just a guess). if they never come back it is not
like the pool suffers greatly in the way of variance as btcguild is 2 TH/s already without them.

but in the end.. i just have to wonder if it really matters to me. sure i want to make more BTC per share.. but if it is only
.05% less do i really care? and what does it matter to the owner of btcguild.. either way his pool operates as he wants.