That shouldn't be surprising. I'm sure this deal has been in the works for the better part of a year at least, so it's highly likely that either Lucas or Disney or some combination of the two has been working up some basic storylines. It will be very interesting to see this all unfold.
Personally, I have no issues with Luke, Leia, Han, Ackbar, whoever coming back for these episodes. I don't want the movies centered around them, but I don't see any problem with cameos or even smaller parts that pave the transition for new characters. I think it would be odd to have a movie set in the relative proximity of Jedi (next 15-30 years) that does not touch on the core characters from the OT. And I would much rather see the characters in person rathern than someone conveniently mentioning "Oh, Luke, Leia, and Han were all killed by a random power coupling failure." See the latest Bourne film for reference on how awful that comes across.
Given what we know about Lucas and the first six movies, I think there's almost zero chance that these movies do not focus on some lineage of Skywalkers. It would seem incredibly awkward to me that we see the development, fall, and redemption of Anakin, then focus on completely new characters that have nothing to do with Luke or Leia for the next three movies. There's actually a lot of fertile EU ground with the Solo kids if they wanted to go that route.