If you have a new Intel Mac then today is your lucky day.
Apple will be including a partitioning and booting system which will let you run Windows XP alongside OSX.
Apple call it Boot camp and i know of a lot of people who will be very happy with this, Apple are even supplying all the drivers you need for Windows. Now you can have the best of both worlds, a high quality Mac Laptop which runs both OSX (for your creativity) and Windows XP (for DirectX gaming among other things), my guess is that when MS finally release Vista it will be installable too.
Here's apples page of info and where you can access the beta verison for Tiger.
This will defiantly open up the new Macs much larger market of people who are stuck with windows due to work or gaming requirements and in the future may even begin to blur the boundary's between the OSX and Windows.
This has certainly made the new Macbooks much more attractive to me, hopefully the new intel iBook wont disappoint and I'll snap one up in the autumn
There are also rumors of Apple release some APIs to allow Windows to run Unviersal Binaries, if they are true Apple are pushing in a very promising direction, the more news i hear about Leopard the more i like it. Only Rumors tho ;)
Edit 2: Bootcamp Likes Linux as well, for everyone who ever wanted to triple boot Windows Linux and OSX… get yourself an Intel Mac.