We've bought into Sun Cluster (AKA Java Availability Suite), and it's my job now to install it. I have 3x SunFire V490s, 32G memory each, 4 physical CPUs (8 cores), each has a quad-gig card (plus its 2 onboard nics) and a dual-port SAN card.
Solaris 10 update 4 (08/07). Sun Cluster 3.2.
Notes on the installation:
So far, it's been pretty straightforward except when I was trying to create the cluster. When it rebooted the first node, it never noticed that the node had rebooted in cluster mode.
This is because the rpc/bind (portmap) service is set to only allow local connections out of the box. A quick "svccfg network/rpc/bind setprop config/local_only=false" (on all nodes) and cluster is now up and running.