I started out with Boot Camp, then used Parallels, then moved to Fusion when the latter became too bloated. Moved to VirtualBox about 4 months ago and haven't looked back. It's faster than the others, the updates are nice 'n small instead of 200+ MB monoliths, and the price, well... it's free!
I like the idea of 64-bit guests on 32-bit hosts, so that I could prep 64-bit kernels on my MBP, for testing if nothing else.

We've been using it for testing software deployments with .Net stuff. It's fast with AMD-V/VT-x options enabled, and the OpenGL acceleration will make our WPF eyecandy fly :D

I've been running Ubuntu, OpenSolaris and Windows XP Pro in the last edition of VirtualBox on a Vista Ultimate system. I just installed OpenSolaris on this new VirtualBox 2.1 and there seems to be a lot of improved performance. Too early to really know but so far I'm happy.

So is the OSE edition available for OSX as well as the 'free for personal use' version?

I must admit, I do like VirtualBox. I used to run it on my old work laptop (running Windows) but I couldn't seem to get it working on Ubuntu, the networking side just 'didn't work'. Looks like it's time to have another go :-)

Quite interesting that it supports AMD-V on OSX, I presume that is for Mac developers and Macintosh users?

Rob

We've used vbox for about 6 months now. It's running on our Ubuntu based CS systems so that a single legacy Windows app can run. (No wine isn't an option yet.)

Networking has been the most difficult part of it resulting in very long access times in it's default mode, or complicated and seemingly fragile custom set ups.

It sounds like they've at last addressed it's number one problem.