Oh yeah, another reason why I think MKXL PC could be happening: Ed Boon said that people who think NRS/WB is (or did) give up on the PC version is "uneducated" and also joked about a Mac version happening.
In other news: NRS was hiring for a new project a few months back. Also, Carlos, the mokap man at NRS started on motion capture work for something not long after/before KP2's release.
Lastly, it's getting to be that time of (every other) year where NRS announces their new big project (aka a new game).
Either way, around E3 there is -- most likely -- going to be some HUGE news about something. If past NRS reveal dates point towards anything, we should be getting an announcement in about 2 - 3 weeks.