Are you still a bit sceptical about running your business on OpenSolaris - a free and power operating system, which due to it's development status is technically unsupported (cos you can't pay for the support)? Well, don't be. Joyant run on OpenSolaris and do encounter problems, however they get them fixed, and quickly too. Check out Benr's recent post on their experience when encountering problems on OpenSolaris.
Can you do this with any other operating system? I don't think so.