ACT and SAT for admission?

<p>I will be applying to some Ivy league and top colleges regular action in January. I have already taken the SAT1's and have not scored that well. However, I have already registered to take the ACT's on December 12,2009. If I submit my application before I take the test, but indicate on my application that I will take the ACT, will the colleges even consider my ACT score? I have already indicated during ACT registration, the colleges I want the scores sent to.
If my ACT score is higher, will the colleges wait and judge my application based on the ACT score?</p>