A search of the Trademark Electronic Search System (TESS) reveals that on December 21, 2001 Midway Games Inc. registered a new trademark. That trademark is Mortal Kombat: Deadly Alliance and it's Very Probable that this is the title of the upcoming fifth installment of the Mortal Kombat series. We have yet to get a confirmation from Midway on this, so we will update on that once we get it. Thanks to PlanetMK.com and MK5.org for the heads up.
UPDATE: Sources at Midway contacted by MK5.org stated that an announcement was coming soon in some form. It's a good chance that Midway's Mortal Kombat Breaking News E-Mail List will be emailed with the announcement, so click above to join the list today before it's too late!