I have been working in US on L1 visa since march 2010, during 2010 I was in US for a period of 220 days.
I got married in December 2010 and my wife joined me in January 2011.
For federal taxes my status will be considered as non-resident alien or I can file as dual-status and claim exemptions for both of us?
Thanks for the help.

If you have not yet filed, you should file jointly with your wife under First Year Choice, with you both CHOOSING to be treated as resident aliens for all of 2010. Even with the need to claim all wrold-wide income earned in 2010, this is probably the best way for you to file.

If you need professional help filing your return, email me at [email protected] or [email protected].