Wouldn't a newer pool be less likely to find a block? I understand that it's pretty much luck, but the pool speed has to have a huge play in things. It seems like a pool with 50Gh/s would be mine a block faster than a pool with say 2Gh/s
True; but the pool with 2Gh/s would reward its miners with 25x the payout because there are less miners to divide the 50 BTC between. Larger pools solve blocks more frequently but divide the block between a great number of people. Smaller pools solve blocks less frequently but divide the block between smaller numbers of people.
Given enough time, everything averages out, but a smaller pools will have a higher variance than a larger pool (meaning you might make more BTC within a limited amount of time, but you might also make less).