MacBook Pro :: System Lock Not Responding?

I read a few posts and articles before i ordered my new i7 MBP with HR matte display about some of the models sometimees froze all of a sudden, now it seems mine has this same issue.. 3 time now, since i got it on the 25th of May. 15 min ago i was sitting and responding to a thread on Facebook, then out of the blue, everything stops repsonding. System is running, mouse is frozen, nothing i can do but to hit the "big button" and restart the entire system. Loosing any work that i might be doing is actually the worst scenario since im a photographer.. Anyone experience these random freeze ups too ? And last but not least, what will Apple do a about it when i contact them in the morning?.. Replace it or let me cancel my purchase and if replaced, how long does that normally take? (Bought it through Apple Store).