Jon Rubinstein, once a prominent voice in the mobile community as he sought to reinvent Palm, has gone quiet in recent months at HP — and that's not often a good sign for any top-level executive's future prospects. Indeed, Rubinstein has apparently left HP effective immediately, according to a report from AllThingsD. The move isn't a surprise considering how many management shuffles HP has gone through as of late, and Rubinstein has all but disappeared from the webOS landscape in its recent transition to an open source platform.

An HP spokesperson simply says that "Jon has fulfilled his commitment and we wish him well," a reference to the fact that he was under contract to continue employment at HP for a set period after Palm's 2010 acquisition. It's entirely possible that he'd plan to leave as soon as the commitment was fulfilled from day one, but it's also possible that the previously mentioned musical chairs on the executive floor simply left him without a seat. AllThingsD says that Rubinstein apparently hadn't been seen on HP campus ever since now-departed CEO Leo Apotheker put webOS in a choke hold in mid-2011, which would suggest his disenchantment with HP's strategy ran deep.