Current support for multisigs is not "rudimentary", it's fully functional. I know how it works and there are existing multisig TXes in the blockchain. The problem is that "official client" doesn't supports creating ANY multisigs - both plain and P2SH.
P2SH is NOT the same as "multisig support", its just a method that will make many different things easier to use, including multisigs.
This is true, but afaik all the devs agree that the way multisig is currently implemented is not a good way. That's why we have BIP 16 (and 17), if multisig was fine just like this then there would be no reason for BIP 16. This is not just Gavin, all the devs agree that P2SH is the way to go.
I mentioned blockchain.info just as EXAMPLE of working multisigs. You don't need to use this online wallet if your client supports either plain multisigs or P2SH/BIP16.
True, but again, the option of using plain multisigs has basically been shelved by the entire dev team, so P2SH is what we're aiming for. And there is no better implementation in the horizon.
The benefits of multisigs will not be available right after enabling P2SH just because there are no clients supporting it for normal users. It's just one step towards really deploying it.
I'm aware of this. That's exactly why I would like to see it enabled as soon as possible so the client developers, not just for the official client, can start working on actual use scenarios and GUI features for multisig. There are a lot of other issues to work on regarding Bitcoin protocol as well, for example the scaling issue. It's difficult to completely move on until this is settled.
P.S.: "next month" is 03.2012
Thanks for making this clear, I appreciate it. By the way I do agree with the way you've handled this whole issue, by deciding that your pool is not the first one to support P2SH. That was smart because your vote has so much weight that it can easily pull others simply by being a large percentage. That's not very democratic.
Also, it seems that P2SH support has increased. It's now at 38% even without Deepbit, which is very impressive in my opinion. Taking Deepbit out of the calculation, it amounts to 55% relative support. With Deepbit the total support would be 70% which is good enough to be totally safe and I'm quite confident that everyone else will upgrade when forced to. Even the miners who don't care for Bitcoin care for their money and mining on a dead end chain would not be smart.