President Obama is well within his Constitutional rights to delay implementation of certain parts of the ACA:
The Affordable Care Act is the law, and Executive Branch has been constitutionally given the power to implement the law. These sorts of delays in implementation are common. Both Democratic and Republican administrations have used them.
The Supreme Court has found that it is constitutional for the Executive Branch to delay the implementation of a law, “As held by former Chief Justice William Rehnquist in a leading case on this subject, Heckler v. Chaney, courts must respect an agency’s presumptively superior grasp of “the many variables involved in the proper ordering of its priorities.” Chief Justice Rehnquist suggested that courts could lose their deference to Executive Branch judgment if an “agency has consciously and expressly adopted a general policy that is so extreme as to amount to an abdication of its statutory responsibilities.” The Obama Administration has not and is not about to abdicate its responsibility to implement the statute on whose success his historical legacy will most centrally depend."
Meanwhile, as the chattering asses freak out over the latest on Obamacare, here's the real scoop on how the delay and the caps will affect Americans:
THE LATEST RIGHTWING FREAK-OUT OVER OBAMACARE