I used the Net::OpenID::Consumer and Net::OpenID::Server modules in production at my last gig and in tests for recent applications -- a dummy server to test consumer stuff -- and they have worked well. I have written to, and received an immediate response from, Brad Fitzpatrick, regarding a problem I was having (which turned out to be operator error and not a problem with the code). It's been 10 months since I looked at the differences between the 1.1 and 2.0 specs but I'm sure if something doesn't work for you and you can work out how to fix/add it you could submit a patch.

I recommend against the JanRain stuff on the CPAN. It doesn't pass any of its tests and while they have a nice community (a friendly and helpful mailing list and good site docs) I had to spelunk some of their PHP and it was lacking in error checking which made a couple of problems I had *much* harder than they needed to be.