http://dtrace.org/blogs/bmc/2011/09/15/standing-up-smartdatacenter/Also, they are actively developing and co-sponsoring IllumOS (and are IMHO the only reason why it didn't die yet), so next time do some research before bashing on a good company.
So, if it OpenSolaris based, then nothing to see here. Community is too small. Who will write and test up-to-date drivers for all new hardware that vendors are pushing to the market each half-of-year?
I had a lot of experience with Solaris (x86 only - people tried to run Informix/Oracle on a cheap hardware) starting from Solaris 7 and onwards. It was always a problem even to install it. And lack of working compiler makes things even worse.
Starting from Solaris 10 they did a lot of work to improve the overall experience, but too late - everyone migrated to Linux to run the same crap.
And I must say, that after it was installed and tuned it was running quite stable as a database server and it can deal with heavy loads, while similar Linux instances failed now and then. But it was 5 years ago. Modern Linux kernels can handle everything quite well.
Joyent probably has fairly homogeneous racks of servers. They only need a few drivers for their entire system, and they have people capable of writing them. If they can port KVM from Linux to illumos, what makes you think they can't port or write a driver?
Update: Oh, come on. I've clicked to the TECHNOLOGY link and what I saw instead of technology review is load of BS. SmartMachines? OK, even I know that one should market any crap with Smart or Easy or Eco or LowFat prefix in it, because, you now, I have a SmartMachine... OK, fine. But what about technology?
Instead of writing that you're building a solution based on fast, light-weight, low-overhead, in-kernel, native virtualization system and RedHat supported libvirt stack, that you're co-sponsoring and actively participating in development process, and here is our contribution and so on, I see loads of BS. KVM is faster than Xen? I know that, thank you. I have a KVM instances running on my Laptop. ^_^
You're using ZFS? Linux native port? FUSE? So, you're active developer and tester? Co-sponsor? You have hired or supporting active developers? Providing a feedback to community? No? You just trying to sell me something you called a SmartMachine, OK, fine. I don't buy it. ^_^