Google, LinkedIn, Twitter, Facebook, Yahoo! - this only stands a chance if you get them all to partake in this discussion and work towards a single implementation that works against all of their platforms.
Aw, c'mon! If you worry about getting the elephants to agree, you'll get stuck in committee adding enterprise cruft. You can move forward without them.
You can build protocols with your fellow smaller companies that have a pressing need to make something work with you, as I believe was the case with OAuth itself (Magnolia and Twitter) and OpenID (I believe LiveJournal and DeadJournal).
If it's good and people are using it well, and you talk about it openly and involve others, it can create its own momentum and become a standard. If not, well, whatever. At least you've moved your own business forward with your partners.
Otherwise, these discussions are pointless.