It was already announced that Immortal would be reuniting for next year's Wacken festival, but now they've also added two US dates to their schedule:
07/13 - BB Kings, NYC
07/15 - The Avalon, LA
Unlike the previous Emperor reunion gigs, I'd actually say these might be worth attending depending on the price. Emperor is incredibly boring live, but Immortal put on a great show when I saw them on tour with Manowar.