The much maligned BlackBerry PlayBook tablet has some good news to hang its hat on. It outsold the iPad 2 at some FutureShop and BestBuy locations last week.

Although it’s a small sample size and only represents one chain, it’s a welcome bit of good news for the Research in Motion.

Unfortunately for RIM though, that’s seemingly where the good news ends.

The company has seen its market capitalization — essentially how much the company is worth — fall about 90 per cent since the end of 2008.

Back then, RIM was worth about $77 billion dollars. Today, it’s worth about $7 billion.

By comparison, RIM’s main competitor has seen its market capitalization explode over this period.

At the end of 2008, Apple was worth about $175 billion. It’s nearly tripled since then to over $500 billion, making it the most valuable publicly traded company in the world.

Market capitalization is calculated by multiplying the number of shares in a company by the price of each share.

RIM shares traded around $150 in the summer of 2008, but opened Monday morning at just $13.31.

It might not get any better for RIM in the near future either. Analyst Peter Misek of Jefferies & Co. recently downgraded his outlook for RIM shares, cutting his 12-month price target to $12 per share.

Apple is also expected to announce the iPad 3 at an event on Wednesday.