Read all about it on the Register.
No great worry I don’t think.
Cas 
No worry for the next 2-3 years.
Maybe MS doesn’t like the upcoming OpenGL ES for mobile gaming?
http://www.eet.com/sys/news/OEG20030228S0023
Well, my only worry is that they’ve backed off from the ARB to release themselves from the requirement to inform the members of conflicting patents.
They have a huge portfolio of graphics-related patents both inherited (SGI etc) and from their own research - they could really mess with OpenGL 2.0 if they want to.
God I hate software patents.
They will support OpenGL long enough to move most major applications over to DirectX - this tactic is so familiar its sickening. This is part of the same strategy used against Java.