RIM has revealed that its stockpile of unsold BlackBerry PlayBooks will set it back $485 million (£308 million).

Despite slashing prices and other increasingly desperate moves made by the Canadian company, the QNX-running tablet has failed to sell particularly well.

But RIM isn't one for quitting, with co-CEO Mike Lazaridis saying, "RIM is committed to the BlackBerry PlayBook and believes the tablet market is still in its infancy."

Uh-huh, uh-huh

Sure, right, yeah. And what about the future of the PlayBook itself? Solid, says Lazaridis:

"Although a number of factors have led to the need for an inventory provision in the third quarter, we believe the PlayBook, which will be further enhanced with the upcoming PlayBook OS 2.0 software, is a compelling tablet for consumers that also offers unique security and manageability features for the enterprise."

Oh yeah, PlayBook OS 2.0, that's the one that will be released in February 2012 that still won't bring basic things like native BBM to the tablet.

We actually liked the PlayBook when we reviewed it, but couldn't get past the lack of core functionality and the hideous dearth of apps. And here we are, nine months later, and the tablet still hasn't met expectations.

No word on a BlackBerry PlayBook mark two yet, but if RIM is as committed as it claims to be to getting itself a slice of the tablet market, we'd expect to hear word of it next year.

From RIM