I think it is typical for programs to require it at matriculation but not at the time of application. However, I'll bet a program would just as soon take COMLEX 2 if you matched there.
That being said I recently got my Step 2 score back and I rocked it. 16 point improvement from Step 1 and I feel like a studied about half as much. In my opinion it is not as difficult as Step 1. I would recommend taking a practice test from nmbe.org. That way you'll get an idea of what your Step 2 score will be before you take it. It predicted by scores for Step 1 and Step 2 within 2-6 points. It costs $45.