Priority Waitlist -- Chances of Admission?

<p>First off, I realize there's tons of threads on CC exactly about this topic; I want to know the implications of getting wait listed and what I can do to maximize my chances of being admitted. I was priority wait listed for the SCS. </p>

<p>What does CMU ask for in terms of senior year stuff? What kinds of things will they be taking into consideration for deciding whether or not people get admitted off the waitlist?</p>

<p>Stats:
SAT: 2400 superscore (2350 single sitting)
SAT II: 770 Chem, 800 Math II
Grades: Maintaining about a 4.5 W GPA, (its around 3.97 UW). For this last semester of school I'll probably have 5 A's and 1B. (The B is in an AP class, as are 3 of the A's)</p>

<p>I was made a National Merit Finalist and in terms of computer science specific stuff, I designed a website for my schools newspaper (the newspaper advisor can write a glowing rec letter for me, if need be), I have a couple of apps about cyber-security (basically they encrypt data on i-Devices) on the Apple App store, and I mess around with code in my free time. </p>

<p>what are my chances with these above characteristics, and will I get the chance to send in additional rec letters? What can I do to maximize my chances of getting off the wait list?</p>