May I remind (or teach) you that as long as there aren't more transactions trying to get into the blockchain than it can accommodate, the size of the blockchain will NOT be affected by the max. block size? i.e. it's the total number of tx that matters, and not how they are spread across the blocks?
Did you understand that 20MB is a maximum and not a nominal size for each block?
So what exactly is Gavin trying to do if not trying to reach consensus with his blog post?
Did you read it? Did you fully understand it?