We really need satoshi now because if he somehow shows up and tell us what he thinks we should do then we might actually agree on one thing and then doing it, I don't think anyone refuses him only if he could speak out somehow.
It is very unlikely that he/she/they appear now to say what the best procedure is,
It can be phased in, like:
if (blocknumber > 115000)
maxblocksize = largerlimit
It can start being in versions way ahead, so by the time it reaches that block number and goes into effect, the older versions that don't have it are already obsolete.
When we're near the cutoff block number, I can put an alert to old versions to make sure they know they have to upgrade.