Apple took its site down and when it reappeared, it boasted a new survey, an updated license agreement and a $99 Mac developer license, far cheaper than before. The perfect price in fact to encourage developers to make apps for a Mac App Store.
Previously a Mac developer license was too expensive for most of the horde of iPhone app developers who have thronged the iTunes App Store.
Building a Mac App Store needn’t mean that Apple’s current approach of allowing developers to sell software via their own sites and through real world Apple Stores is going away but it would be a good addition.
Creating an Mac App Store would mean a far larger selection of software. It could also bring more new games to Macs as well the (very welcome) ports like Monkey Island or the rumoured Steam for Mac OS.