noob.com, and it definitely features a Mortal Kombat logo and was registered by Midway, so it seems official. It features a countdown to April 17, a picture of two eyes, a picture of some animals, and some numbers.
Reader Batzarro did a little decoding and decided that (if you allow that the animals each represent their first letter in their name) that it translates to "Ice Rage." We decrypted the yellow numbers below using a numerical alphabet code and got "FREE TOUCH KLOSE." OK, so you officially know as much as we do, what's the verdict? Gag? Or something else?
UPDATE: Hmm, where to start? OK, so 1. This page belongs to MK creator Ed Boon. 2. Hidden on this page is the message "It is with deep regret that after over 20 years with Midway, I will be leaving as of today to pursue my dream of becoming a chef. I will never forget the incredible experience I've had with such an amazing group of talented people." So it seems the actual 4-1 gag is Boon leaving for cheffing (cheffery?). Hope that clears it all up.