| Well, generally it is very hard to tell, but on the surface and with the marriage penalty still existing, one would generally advise you to run the tax program with both scenario, ie Married filing joint and with Married filing separate.
Most tax programs today have the ability to project the tax liability using both scenario's, and so the taxpayer can determine which filing method is most beneficial. So, I would recommend that you direct your CPA to prepare both scenario's and you can then decide which one offers the best tax refund! | 
