...make sure you touch base with vendors that you have not yet paid a deposit or signed a contract. Or, even if you have, just send a follow-up hello.
I followed up with my ceremony site & caterer just because it's been since Sept since we made arrangements. Imagine my surprise when I was told our "hold" on the ceremony venue expired in October. Yikes! The space was still available & I sent deposit immediately, but had I not followed up with a couple questions, I never would have known we didn't have it!! For the record, we were told we didn't need to place our deposit until 2012, but the contact person also changed in the meantime.
So, I would just recommend touching base with those vendors you may have booked first thing, but haven't really had to speak with since. Happy New Year!