I had similar positive results as @RonGouveia: Upon entering the e-mail address I was using in the old Community Forums, it just picked up my respective user ID.
And My Discussions ""are"" showing on the Your Discussions tab, however it doesn't appear I'm still 'e-mail subscribed' to them. Couple other things I noticed: doing a Search defaults to searching across all Groups, not just My Groups, but can click on the left to filter although a bit of a pain to do that every time. Also, search results appear to default by Most Relevant, not by Most Recent. And having trouble with the Signature setup.