The changes in the last year were "soft forks" -- forks that required all miners to upgrade (if they don't, their blocks are ignored), but that do not require merchants/users to upgrade.
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A couple of random, half-baked thoughts I had this morning:
If you think that the block size should stay at 1 megabyte forever, then you're saying the network will never support more than 7 transactions per second, and each transaction will need to be for a fairly large number of bitcoins (otherwise transaction fees will eat up the value of the transaction).
If transactions are all pretty big, why the heck do we have 8 decimal places for the transaction amount?
Don't get me wrong, I still think the bitcoin network is the wrong solution for sub-US-penny payments. But I see no reason why it can't continue to work well for small-amount (between a US $1 and $0.01) payments.
If there are a very limited number of transactions per day and billions of dollars worth of BTC being transacted (that's what we all want, yes?) then obviously each transaction must be large. So, again, why bother having 8 digits after the decimal point if each transaction is hundreds of bitcoins big?
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Second half-baked thought:
One reasonable concern is that if there is no "block size pressure" transaction fees will not be high enough to pay for sufficient mining.
Here's an idea: Reject blocks larger than 1 megabyte that do not include a total reward (subsidy+fees) of at least 50 BTC per megabyte.
"But miners can just include a never broadcast, fee-only transactions to jack up the fees in the block!"
Yes... but if their block gets orphaned then they'll lose those "fake fees" to another miner. I would guess that the incentive to try to push low-bandwidth/CPU miners out of the network would be overwhelmed by the disincentive of losing lots of BTC if you got orphaned.