The Tivo v. EchoStar Communications patent suit has been stayed pending the outcome of a patent reexamination (see a recent article). I believe the reexamination option should be discussed more frequently with clients facing patent infringement lawsuits. They are a good way to test the strength of a patent without paying the crazy costs of litigation.
In essence, patent infringement requires two phases. First, there is the Markman hearing to determine the scope of the claims of the patent; and second, there is the trial stage where the alleged infringing device is compared to the claims of the patent (as determined by the Markman). Of course there is also a damages phase but we'll leave that for another day.
Since the Markman hearing determines the scope of the patent, patent cases are frequently won or lost at the Markman hearing. After all, what the patent actually means will be vital in determining infringement, right? It is this phase that is essentially argued in reexamination. The Requestor provides references against the patent and the patent examiner determines the scope of the claims in the patent in view of the patentees response(s).
As already suggested, patent reexaminations are conducted before the United States Patent and Trademark Office (USPTO). Reexaminations seek to determine the scope of the patent when there is a "substantial question of patentability". Rexaminations allow a patent to be re-evaluated or reexamined by the patent office in view of art cited by the Requestor (the party that requests the reexamination). While a reexam is not always declared, they frequently are.
Essentially there are two flavors of reexams. Ex parte and inter partes.
In an ex parte reexam, the Requestor requests a reexam in view of properly provided documents. If declared, the Patent Examiner reopens the case and issues one or more additional office actions. The Requesting party does not actively argue the case but is provided with copies of the reexam during the process. Thus, the Requestor does not pay a litigation team to argue against the patentee after a reexam is declared.
In an inter partes reexam, the Requesting party actively participates in the reexam. However the issues raised by the Requester may not be raised in later actions.
Contact a patent attorney to further dicuss whether a reexam would be right for you!