If bitcoin 0.9.2 was to come out with the hard fork so that newer versions no longer allow centralized mining I would rather support it and have everyone forced to use P2P mining.
I think the best solution would be if we as a community decided that each mining guild should not exceed 10% of the total network rate. This way people are still ensured regular blocks and it would be much harder to get enough groups together for a 51% attack.
I am not quite sure how you would get pool owners to accept a change that would negatively affect them. At best they would just subdivide their pools into smaller pools and carry on, possibly obscuring their ownership.
Not the pool owners, the miners. And the second problem would be a matter of not signing up for someone with unknown owners. But of course that won't happen until we have an actual 51% clusterfuck.