I took the plunge and installed Windows 7 RC today on my laptop that I am going to be using for work. The install went flawless and via Windows Update I had all of my drivers as well. The problem came when I realized that I had installed the 64 bit version and the lack of a client for non-SSL Cisco VPN. After reading several places I found that the best solution was NCP's Secure Entry Client. They recently released a BETA version that supports Windows 7.
I must say I was pretty impressed. I installed it and did a profile import and I was up and running. It's not free ($144) but if you need support for 64bit OS's it works great.
You can get the client here: