A couple of weeks ago HP announced its support for the StorageLink technology that Citrix is offering inside the Essentials management suite.
StorageLink allows the XenServer and Hyper-V administrators to manipulate the SAN LUNs directly from inside XenCenter and Hyper-V MMC console.
HP is supporting this technology on its StorageWorks SANs, including EVA, MSA and LeftHand Networks arrays.
With this move HP may be trying to consolidate its position in the SMB market, as the announcement comes just a little before the Citrix one about a free version Essentials for Hyper-V (called Express Edition) that includes the StorageLink layer.