I think Windows 7 (or whatever they call it) will not be out until early 2010 (next year) so you may have a long wait.
rojash is rather scathing but I dont think Vista is bad as that.
It has not been the resounding success that Microsoft wanted, and there are some things that are not good as you may wish, but it does not take too long to get used to Vista.
You can change the Vista interface to make it look like XP if you wish, to make it easier to learn.
Vista is more secure than XP, but you may get fed up with Vista constantly asking "do you really want to do that" nearly every time you try to do something.
And if you have any old hardware or software you want to use with Vista you may find the hardware does not work (no Vista drivers) and the software may not install or work under Vista.
I have PCs at home that run both XP and Vista and I have to say I give XP 10 out of 10, but Vista probably about 7 out of 10.
We have Vista on our family PC and all my family enjoy using Vista as it is more colorful and attractive.