Hello,
I think it would be nice to get a Sun Thin Client, but I see a few issues with that.
1) They don't run on SPARC anymore, but on RMI Au1550 - which is based on the MIPS architecture. I would want to deal with Sun to get SPARC.
2) As far as I know, they won't work without a server on the other end.
3) Because of #2, they are very weak on components such as CPU, RAM, and Storage. CPU isn't too bad - ~500MHz, but RAM is very low - I don't know what the current ones have, but the SunRay 150 had only 8MB of RAM (I think). And the Storage is (again I think) only enough to hold software enough to connect to the server, which is meant to do all the real work.
I think that if they made a thin client like they currently have (the basic design is there, in my opinion) and switched back to a SPARC (T2 - would be awesome) ~1.0-1.5 GHz, put in 1GB RAM, and gave it 16-32 GB RAM (maybe CF in RAID 1) - that would be a great little system. I could still work in a client-server environment, but would have the ability to work as a stand-alone setup.
But, just dreaming I guess.