Look for a darker FO3:
It was known to me that Fallout 2 was a bit...well...shall we say, full of everyone's little tidbit. Possibly a "too many cooks" problem, with everyone wanting to put in their own little easter egg and such. They have already realised this, and I strongly believe they are going to go back to the darker Fallout 1 formula, and possibly make one or two (perhaps more), grand pop-culture references, and some smaller and numerous other ones. I don't think it will be even half as rampant as Fo2's references were.
I don't see Yoda or anyone else becoming an NPC, but I can see a possible encounter, perhaps a reference hidden somewhere.
Fallout 1 had it's own neat blend of references, and they were a challenge and a joy to figure out at times when you found them. But Fo2 had too many references, and you actually had to weed them out to find the game at times.
Here's to a darker Fo3....