Long time forum member VieuxJules has posted in the forums with his experience installing the new Windows Server 2012 Essentials beta on his HP MediaSmart Server EX470. Note that he has an upgraded server, most importantly increasing the stock 512MB of RAM to 2GB. While he installed it on the EX470, this process should work with any model of MediaSmart Server or Data Vault.
Here’s what VieuxJules had to say about the experience:
First impressions: most notable benefit is Spaces (kind of an evolved Drive Extender with different implementation choices). Also the server can be backed up (like in WHS2011). The computers are backed up in a similar way as to WHS2011. Oh, and it works on the MSS.
But there are some showstoppers: supports only Win 7, Win 8, and Mac OS.X 10.5 to 10.7 (I should experiment with a Mac in the near future to see if it will backup a OS.X Lion!), I also upgraded a laptop to Win 8 Release Preview for testing purposes; the price (425$) but you own a business server that does “home” things; a domain instead of a workgroup (I read somewhere you can disconnect from the domain and step-back in a workgoup, but I have not tested this).
Visit the forum topic here and post in the comments if you try it yourself.