This version comes with a number of very impressive new features. If you have Windows XP installed on another partition using BootCamp, Parallels can use it directly.
Graphics performance has been increased up to 50%. You can drag and drop files between Mac and the Parallels-hosted OS.
Windows applications can be displayed as if they're simply OS X windows. This looks quite neat. Here's a screenshot ...
All up, it sounds like the next release will be well worth waiting for.