It is not known at this time what, if anything, this means for Mojang. Of note, Markus "Notch" Persson has certainly voiced his opinion on the matter, stating that he "will throw piles of money at making sure they don't get a cent". Little else is known about the lawsuit at this time.
Notch has made the lawsuit PDF available for viewing, which you can see by clicking here. He has also posted a detailed write-up on his perspective on software patents - you can view it by clicking here.
Uniloc appears to be suing numerous other gaming producers allegedly violating this patent, including Square Enix, Electronic Arts and others.
Any further specifics of the case will be covered as they develop.
UPDATE: Ric Richardson has posted his views on the situation as well, which you can read by clicking here. It is important to note that Mr. Richardson has had no direct part in the lawsuit of Uniloc vs. Mojang.
This week, David and Toby talk about Minecon 2012, Creeper clothes and other awesome Minecraftiness - check it out!