the only major difference in 2010, aside from all the new functions, is the data macro bs. And that should never be used, as it's a pointless addition to the program.
2010 does still run mdb files. But if by some miracle they don't, I'm sure Bob Larson will correct me. Wow, shouldn't have said that, but I like teasing him.
The macro structure is also different, which may very well be part of the causality of backward compatibility being a problem.