This mostly comes from new tax laws that will be taking effect. Some Credits will not be able to be filed up until March 2013.
The following tax forms will be accepted by the IRS in late February or into March after updating forms and completing programming and testing of its processing systems. A specific date will be announced in the near future.
Now what do you take about these credits and dedications?
you can see the whole story here http://www.irs.gov/uac/Newsroom/IRS-Plans-Jan.-30-Tax-Season-Opening-For-1040-Filers