The Dead Space sci-fi horror games have nothing to do with the Mass Effect sci-fi shooter/adventure games, other than that they're published by the same giant corporation, EA. But now they're ever-so-slightly crossing over.
EA is letting people who have a Mass Effect 3 save file unlock special Mass Effect N7 armor in next month's Dead Space 3. We're checking with EA about whether the unlock works across platforms, if, say, you played ME3 on PC and will play DS3 on PS3.
UPDATE: An EA rep confirms that this is platform-specific. You'd have to be playing Dead Space 3 on the same console (Xbox 360 or PS3) as you played Mass Effect 3.
Mass Effect armor is also unlockable in Final Fantasy XIII-2. Everybody's wearing it!
Dead Space 3 - Mass Effect N7 Armor [YouTube]