If one or even few of the biggest pools goes down, miners will switch to another pools. They will survive, don't worry, rovchris. In addition, there is p2pool.
Increasing of transactions time is also not a big problem - if it be perceptible, users will begin to add more fee to their transactions which would entail increasing of miners profit. This mean more hashing power in the network. So the problem will be solved.
Mate I do worry - Prove that the other pools can cope with that sudden influx of load. The most likely scenario is they will head for the next biggest pool (BTCGuild?) and then that will go down like a house of cards and as you go down the chain each pool can cope with less load. Its quite feasible that the miners themselves will accidentally knock the pools off line as their fail overs are handled automatically by the mining software.
Also prove that the smaller pools are not going to die off further as the difficulty increases and their hashing capacity does not grow accordingly .
BTCMine.com is a perfect example - I will be amazed if that is still around in a few weeks. Currently its at 10 days and still has not found a block and could possibly go to 30 days based on 90 million shares which is what one round was on Slush's pool. Those miners will leave because they can not go that length of time without a payment. They will almost certainly move to Slush's pool as it is the only other score based pool. Ill be honest I already have.
Any large company that would like to involve themselves with Bitcoins will be looking at these factors. I can tell you categorically that they will not touch BTC with issues as big as these.
The other issue is - with a few big pools it is much easier to compromise the network.
You may only have to DDOS 5 sites and then everything stops. Where as if it was highly decentralised by solo miners it is impossible to DDOS.
Bitcoins have morphed into something never envisaged by Satoshi and that is quite clear if you read the whitepaper. One of the founding features was decentralisation.
None of you guys have made it clear why the network is not going to get more centralised!
Is it not the pool operator that dictates the transaction fee and not the miner?