While Google Inc. (GOOG) has a credible record when it comes to mobile operating systems -- having made the booming Android operating system -- its track record when it comes to flagship hardware is decidedly more mixed.  

Every major OS release Google designates a "flagship" hardware model.  For example Android "Eclair" 2.1 was fronted by the Nexus One.  For Android "Honeycomb" 3.0 -- Google's new tablet-specific Android distribution -- that flagship model was the Xoom.

The Xoom has been billed in the media as a promising, but unpolished product.

Set at a lofty price of $599, it has failed to compete not only with thinner, lighter iPad 2 from Apple, Inc. (AAPL), but also cheaper Android tablets.  Yet another sales analysis has landed and the picture sure isn't pretty.

The Nexus One wasn’t a sales blockbuster, and according to some estimates, the Motorola Xoom may be doing even worse.

Global Equities analyst Trip Chowdry claims that Motorola (MMI) is sitting on an enormous overstock of Xooms.  According to his estimates, the company produced between 500,000 to 800,000 units, but has only sold between 5 to 15 percent of them.

That estimate means that the best-case scenario is that the Xoom has moved an anemic 120,000 units in the two months since its release.  And the worst-case scenario is simply crushing -- that only 25,000 Xooms have been sold.

And it may only get worse.  South Korea's LG Electronics is preparing to release its G-Slate tablet, priced at $529 USD.  And in June two new Galaxy Tab models from Samsung Electronics (005930) land at under $469 and $499.  And that's not to mention Dell's Streak refresh and other coming products. 

Even more troubling for Motorola is the fact that ASUS today launched its Eee Pad Transformer Honeycomb tablet that is priced at $400 for a 16GB Wi-Fi model and $500 for a 32GB Wi-Fi model.

In short the outlook for Xoom isn’t very promising.  The fact that analysts once estimated that the device would sell 3 to 5 million units makes its sales even more embarrassing.

The tablet is boldly venturing into waters of commercial disappointment seldom sailed before.  Its flop may only look graceful in light of the ultra low bar that Microsoft's infamous Kin project set for a mobile failure.  But that's not saying much.