Don't worry I can pretty much guarantee to you that 5.2 will hit mid to late march. That puts it perfectly in the 6 month timeline for a new raid tier. It also means it will land perfectly just before the financial year first quarter finishes to get those to unsubbed players who were just waiting for patch 5.2 to resub for raiding again back in time to count for the shareholders report.
Expect a 2nd or third week in march launch 12th/13th or 19th/20th March 2013 release for 5.2 patch. My guess would be for 19th US release and 20th EU.