No one has any idea as to what the actual Windows 7, announced at PDC, will be like. But you can have a rough idea, after seeing all those pictures floating on the web, that the upcoming Window will be exactly like Vista.
Only a few features have been added. If you cannot wait anymore until the release of Windows 7 you can try out Windows 7 themes for Windows XP.
In order to install the theme on Window XP you will have to patch it with uxtheme.dll file.
Window 7 Theme for Window Vista
Window 7 Theme for Window XP
How to Patch uxtheme.dll File
1. Download it from here
2. Run .exe file
3. Press patch button, and wait patiently
4. Restart after patching is done.
However, if you want to replace the file manually, then download it from here, and paste it in C:\Windows\system32\. reboot your system for changes to take effect.
You will now be able to use 3rd party themes without any problems!