I'd be prepared for it not to improve their friendship-- how would that work? It will add some stumbling blocks. Over time, it's more likely than not that the friendship will naturally fall away due to the differing social groups (at least unless you live close by in the same neighborhood), but it's not the end of the world.
We do live fairly nearby (about 4 blocks away) and they have a ton in common. What is apparently happening now is that they are becoming more aware of their different academic skills and our son is pretending not to know things and his friend is refusing to try things when they are working together (which happens a lot within the kindergarten setting since his buddy is cognitively similar but hasn't found his stride with reading yet--math is another story, our son's math scores are above the 99.9th percentile).
So, I am hoping that if they can have shared experiences (after school program, summer camp, weekend activities) that don't focus on academics, and get their academics separately, things will improve between them instead of it being the kind of push/pull they have now.
