Lots of competition here.
VMware has a vSAN...sort of. it's nice to see they finally got AHCI support added in, (you know, because it's really not all that important and blame the user if they don't buy according to the HCL. Or you know, can't afford to buy according to the HCL. Or happen to think that bog standard industry interfaces that are built into fucking everything should be supported. Little things.) Despite this, the attitude presented to the hoi polloi by those in charge has left me with the square root of negative zero warm fuzzies on their ability to give bent fucks about "things used by companies that aren't the top 20%". At the moment, I'm really not predicting a huge uptake. By the time VMware pull their finger out, they'll be fighting an uphill battle against entrenched players, even with their "built in market" of ESXi license holders.
HP has Lefhand, and Lefthand is good. Unfortunately, it's priced out of the SMB space and there is a general feeling of neglect to the product. Few announcements, little rah-rah and less discussion of uptake. That sucks, because it's actually quite awesome.
Nutanix and Simplivity can simply choose tomorrow to turn their offerings into software-only vSANs as well. Nutnaix has a massively evangelical user base, many of the top minds in the field and an established presence around the world. They are full steam ahead, support multiple hypervisors and show no signs of slowing down.
Simplivity have focused on their backup and dedup tech. They view themselves less as a private cloud enabler and more as a storage play. They've got good tech, great people and a fighting chance amongst the morass.
Whichever of these companies you feel is likely to win - and for whatever reason - the addition of Maxta to the mix can only be excellent for end users. More choice, more competition, more pressure to innovate, differentiate, diversify and push the boundaries of software defined storage.
About goddamned time.