As you may or may not have heard, Harrison Ford broke his ankle on the set of Star Wars VII the other day. Its a pretty severe break so its going to be months before he's back on track and moving around again. This means the film is going to be pushed back, or the script rewritten and Solo's part culled a bit.
I'm torn on it. I love Ford (best movies are not Star Wars though, but Bladerunner and Mosquito Coast), and Han is a really cool character. On the other hand, the franchise needs to capture a new generation of viewers to keep it alive.
Who can say at this point. Being a little involved in production of things however, I can say that the producers and director are having many, many conversations about what best path to follow! To them I say "Good luck!"