Subscribed.
I don't run any production FreeBSD servers on Parallels, but I do benefit from being able to run test VM's before deploying for real. FreeBSD 8.x and 9-STABLE are running fine for me inside Parallels Desktop 6, and they ran fine in PD 5 before I bought the upgrade.
If you break FreeBSD under PD, you can rest assured that PD6 will be the last upgrade that I buy. Thanks!