What are my chances?/How important is the SAT writing section?

<p>I am a student in the class of 2011, and have a 3.9 GPA at a strong private high school while taking several AP/Honors classes, and on the SAT I got 730 for CR, 740 for Math, and 670 for Writing. I have taken only one official SAT, but have taken lots of practice SAT's. The 730 was by far my best CR score, 740 on Math was expected, but 670 for writing was a little below what I wanted (goal:700+). I'm looking at USC, Northwestern, Georgetown, Duke, Stanford, Rice and Cornell for college, and I'm wondering if I need to take the SAT again in order to get into these schools. If I take the SAT again I think I can bring up my writing score, and maybe increase my math score as well, but I'm worried about tanking next time on the CR section. Is it worth it to take the test again to bring my superscore SAT up to a 2170-2200 from a 2140? I've heard many schools do not consider the writing section, or at least consider it less than the CR and Math, but I'm wondering if the writing section is becoming more important since it's been around several years now. How important is the SAT writing section right now, and based on my scores and GPA, should I take the SAT to increase my writing score, while risking a decrease in CR (In the past I've had CR scores between 590-660) that may make my 730 look suspicious? What are my chances at these schools if I don't take the SAT again? Any suggestions or recommendations would be greatly appreciated. Thanks.</p>