Research In Motion and suitor NTP will appear [paid subscription req] in U.S. District Court for the Eastern District of Virginia February 24th to decide a shutdown of US sales and service of BlackBerry. A shutdown has been possible for quite some time, but a decision could finally be reached on or shortly after this court date. Lawyers are uncertain that an appeal would stop a shutdown if the court issues the injunction.
NTP is suing RIM for patent infringement and has already received a ruling that RIM has indeed infringed. Complicating the case is the US Patent and Trademark Office preliminarily rejecting all of NTP's patents that were infringed upon. So far the judge in the case is unwilling to wait for a final ruling from the USPTO despite the potentially crucial information that could come of it.
The US Supreme Court recently opted to not hear RIM's case.