Yes. I use TouchDown. It. Is. Awesome. Eval version does most things, but the app is fairly inexpensive and totally worth it. Been using it on my phone for a year.
Ok, so now I have a follow up. The issue with Touchdown not working was the IMEI integration, the team at NitroDesk have released a new beta that removes this and the application works a treat now. This is really nicely engineered for the tablet platform, and integrates pretty completely and seamlessly.
You can access the beta at http://tinyurl.com/tdbetadroid
The nice thing about this over the app in 2.2 is that it also syncs tasks and notes.