It just means apple will be able to sell more software, big deal. I think its an intelligent move really, if they can prove that the Mac OS is, in fact, much more advanced than windows XP the only way to prove it is to make it as widely available as possible. On thier main compeditors platform. They will sell more and make the market for OS's much more competitive therefor prices for both may fall and features will be added and issues addressed much more quickly.
This is something they should have done years ago.