Can you only claim deductions on an LLC (or S-corp) in the same year it was set up?...?

I bought my first house in September 2010. I am expected to make $50,000 on a lease option in early 2011. I bought the house in my name but plan to transfer in an entity asap. I have been saving and recording ALL of my personal & business expenses for 2010. Should I set up a LLC today so I can claim my expenses for this year. I plan to flip several houses this year. Thank You