Some of my view:
Actually many people here are just hoarding coins, there are not really a lot of transactions happening everyday, especially miners who connected to a pool. If we remove satoshi-dice, I think at least in the latest 2 years it will still work fine. Satoshi-dice is just an execellent example of no matter how big the block size is, there will be applications flood that space with meaningless transactions
And now imagine Satoshi-dice translated in 100 languages and used daily by 100 million people. And now imagine imagine another 100 Satoshi-dice type of service. That's going to be a problem, no matter how big the block size is.