"Microsoft and its supporters have argued that the standard for invalidating patents is too high, while i4i's supporters claim that Microsoft is trying to lower the standard to suit its own ends."

"I4i sued Microsoft in 2007"

"Microsoft has tried a series of appeals as well as taking the side path of challenging the validity of i4i's patent with the USPTO, a move that the patent agency rejected last summer"

"It's now a battle over whether we will have an effective patent system," Owen added.

http://itmanagement.earthweb.com/entdev/article.php/3928826/Big-Players-Take-Sides-in-Microsoft-Patent-Suit.htm