I've taken the leap and converted my desktop to run Indiana Developer Preview 2. It's looking pretty nice so far, but as the Preview title suggests, running this as a primary development machine is still a bit on the bleeding edge. So, I'm filing or updating bugs at http://defect.opensolaris.org as they pop up.
Getting VirtualBox running was one of my top priorities so that it remains easy to test in-development bits on Nevada too. So, I downloaded and installed VirtualBox for my amd64 system, and got this:
$ /usr/bin/VirtualBox ld.so.1: VirtualBox: fatal: libX11.so.4: open failed: No such file or directory Killed
So, I found (well, David pointed me at) Indiana bug 512, which describes the missing symlink. Since it's just a missing link, I was easily able to work around it.
# cd /usr/lib/amd64 # ln -s ../../X11/lib/64/libX11.so.6 libX11.so.4
Now I can launch /usr/bin/VirtualBox, and am installing Nevada right now.