This was a bit trickier than Ubuntu in VirtualBox on OpenSolaris. The screen resolution was resolved by the Developer Preview 2 install inside VirtualBox, but the OpenSolaris VM had no networking. How do you download missing stuff when you have no network access?
You get the .iso for the ae network driver from Alan Burlinson's blog. I do not have bunzip2 on Windows XP, though you can probably get binaries somewhere. Instead I unzipped the .iso on another system, stopped the OpenSolaris VM, and then mounted the .iso.
Next I followed the directions in the Readme file for the driver ( more or less ;-). After a reboot of the VM, the network seems to work fine.
