Some of the prominent features of RDC 7.0 are
1.Windows Media Redirection
2. Bi-directional Audio
3. True Multi-monitor support
4. Aero Glass support
5. Enhanced Graphical Display
6. Language Bar Docking
7. Easy Print
8. Web Single SignOn
9. Status and Disconnect System tray icon
10. Launch apps and desktops from RemoteApp and Remote Desktop client (Windows 7 client only)
Click here to download and install RDC 7.0 client for your version of Windows XP and Windows Vista.
Also, click here to view the feature comparison posted by the RDC client team blog.