Yes, the title is confusing. GHC 7.02 is significant because it will be included in the next Haskell Platform release -- GHC 7.01 was only available separately, and was not much installed.
GHC 7.01 was also a time of upheaval in the code base, with an almost total rewrite of the type checker. This was a bit buggy at first, but early experience with 7.01 means that it is much more polished in 7.02.
Yes, but that's usually in the second digit (e.g. 2.4 is stable, 2.5 is development) - switching from unstable to stable in a nominal patch release (third digit) is at least uncommon.
