AFAIK the only protection is SSL + certificate validation on client side. However certificate revocation and updates in miners are pain in the ass, that's why majority of pools (mine including) don't want to play with that...

Why would miners need updates? If they implement the standard SSL infrastructure you can change certificates and keys without needing to update miners.

Besides, when it comes to financial services SSL is essential, I'm kind of surprised it wasn't already used everywhere. I wouldn't use an online bank that didn't support SSL, I would see it as a a sign of serious problems. Heck I wouldn't even use webmail that didn't support SSL these days.