I personally believe that PerlMonks in 1.0 times was more 2.0ish than quite a lot of other sites. Actually it was and still is different from most other fora out there - in a positive manner IMHO. Now that we're in 2.0 times I would say it is 1.5ish, but speaking as a person who's generally fond of 2.0's typical doodads, bells and whistles, I don't see any of them as being particularly fitting for PM nor do I see the latter to benefit in any particular way from any of them. Put it in another way: were PM "2.0", it wouldn't pretty much be PM anymore.
Granted, it's not such a black/white situation: occasinally I wish PM supported asynchronous votes and had collapsable nodes and nodelettes, perhaps with dinamically loaded info. But little more. OTOH there's been at least one attempt to bring such goodies to PM without touching its basic structure.