I am in US in L1 visa and I meet the resident alien requirement for tax purpose (as I lived already more than 183 days in 2009). But my wife and kid are still in Europe living there. They came to visit and went back. SO
1. what would be my filing status for this year?
2. Can I claim any benefit?

1. You can file as married filing jointly or married filing separately.
2. If you file joint return, both of you must report worldwide income. Claim your kid as dependent. Attach W-7 (ITIN applications) with your tax return.

Thanks MukatA for clairification.

If we submit the worldwide income for both of us, can We both also claim the foreign tax credit? Since we both have paid the taxes also in Europe.
- they already have ITIN from our previous stay in USA, 10 years ago. I think we can still use that ITIN.

Yes, both can submit Form 1116.
Yes, you can use the ITIN.