if the pool switched to PPLNS, would that mean that it would pay out rewards as they are earned? in other words, there would be no delay?
Probably not, back when eligius was proportional there was a delay as well.
It's a bad thing to have a lot of small transactions for payout, because when you spend the coins later, you have to pay higher fees and it pollutes the block chain.
Something just came to my mind that could shorten the payout queue, although I'm not sure if it works, and it seems rather dangerous to do. Why doesn't eligius put transactions with a very high fee (input: maybe 50BTC, output: maybe 0.01BTC, fee: 49.99BTC) in its blocks. The fee should be available in the generation transaction instantly and can be used for >50BTC payouts.
Just need to make very sure that transaction is not broadcasted to the network for other pools to pick up..
And now that I mention it, of course: it's a bad idea, because the block might be orphaned later and then others can put the transaction into their own block.