Permanently keeping the 1MB (anti-spam) restriction is a great idea ... if you are a bank. Those favoring a permanent 1MB cap saying that Bitcoin can still be a financial backbone of sorts they don't know how right they are. The problem isn't a limit in general but that 1MB is so low that under any meaningful adoption scenario it will push all individual users off the blockchain to rely on trusted third parties. 1MB is useless for end user direct access but is sufficient for a inter-"bank" settlement network.
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Conclusion
The blockchain permanently restricted to 1MB is great if you are a major bank looking to co-opt the network for a next generation limited trust settlement network between major banks, financial service providers, and payment processors. It is a horrible idea if you even want to keep open the possibility that individuals will be able to participate in that network without using a trusted third party as an intermediary.
I just wanted to point out that Monetas / Open-Transactions is working on a solution that eliminates the need to trust third parties.
So the bulk of transactions could move off-chain to Monetas notary servers, and a notary would be unable to steal the coins, and would be unable to falsify receipts or change balances without a user's permission.
With the vast majority of transactions occurring safely off-chain on Monetas notaries, any user would still be able to perform on-chain transactions when necessary -- it would just be a lot more rare, and would usually consist of a transfer from one voting pool to another.
So keep your 1mb limit if you want, it will definitely benefit Monetas.
Sounds like the OT technology might be a promising way to manage the internal accounting inside of a sidechain. I'll be interested to see how it performs in such a capacity and might entrust a small fraction of my stash to a sidechain which employs it. If they do other interesting things as well of course.