Yes and no. The beta was to move everyone to the Wave UI. They could have/should have built the Wave protocol into Gmail. In this case, Wave really was beta, and not a working beta like Gmail had been. I think that was the problem. People saw the Wave UI and assumed that was the end product.
Basically, Facebook is doing what Google should have done, baking the new stuff into the existing UI set.
Wasn't this by getting everyone to switch to Wave instead of email/GTalk? Facebook seems to have a more realistic approach here.