FWIW..Ron, BaNosser, I ran this question by a Patent Attorney friend a few days ago, and he provided the following answer. Not sure if it has been answered, been under the weather and work has been super busy of late, so a little behind on my reading. Hope all is well! Good luck everyone.

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My Question:

As I stated before, the Discovery phase has passed (February 23rd), and in reading all of the Pacer Docs (I have a Pacer Account), I see no mention by any of the defendants pertaining to Prior Art. They do challenge the patents on the basis of “invalidity”, but they do not specifically mention “Prior Art”. Can I assume that they will not be using “Prior Art” as a defense, or could this come up later in the case? The Markman is scheduled for early may, 2007.

His Answer:

You probably won't see anything pop up on pacer that explicitly states prior art.  However, if you saw something like motions for summary judgment based on invalidity, then this very well may be a motion to invalidate the patent based on prior art.  There are only a handful of ways to invalidate a patent, and the most typical one is invalidating based on prior art.  Some of the districts have the motions scanned in and you can actually pull them up.

The Markman hearing construes the claims of the patent.  A patent is basically broken down into the specification (description), drawings, and claims.  The claims are what define the rights in the patent.  The Markman hearing will determine what each claim means.  Once the claims have been interpreted at the Markman, the parties then typically file motions for summary judgment for (1) infringement/ non-infringement and (2) invalidity.

In patent cases, the Markman hearing often determines the outcome of the case.  The plaintiff is trying to interpret the claims so that the accused product infringes.  Obviously, the defendant has a different interpretation. If the plaintiff gets their interpretation, than more times than not, it is game over.