Admittedly I know the Xsigo product very well, what it does and where it fits.
Some observations on this great article:
Xsigo will connect any Server to any Storage to any Switch, it's agnostic and uses industry standard HBAs, so zero brand specific or proprietary tie in on the connectivity at all. It's a true open platform. As far as I know it's the only IO director product that offers QoS (Quality of Service); Cisco and HP currently do not.
Cisco acquiring NetApp? Better send some thermal underwear to Hell... we heard the same ramblings about Oracle buying NetApp last year just before NetApp bought LSI's block disk division. I shudder at the thought of the Network giant buying the last of the Channel friendly storage vendors.
More importantly what is the long term synopsis for Xsigo? They are profitable even though it's a very young company. I always believed that they'd either float or Dell would scoop them up, but I don't believe the latter will happen.
The bottom line is that virtualising the IO stack is the final building block in the enterprise virtual strategy, after all we can virtualise the desktop, servers and storage, so virtual I/O makes perfect sense.
Xsigo's offering is not unique but it's the best of the bunch out there right now..