Post CAT 2012 result IIM aspirants will have to write WAT (Written Ability Test) which will be given to you with some assigned topic and you will have to finish in 10 minutes.
Remember that WAT is a test on your writing skills hence your handwriting, creative writing, synchronization of thoughts are at stake.
Keep it top of mind that till now you have excelled in entrance test and based on your high percentile score you have been shortlisted by IIMs. Now your soft skills like communication, confidence level, attitude and body language will be judged by admission selection panel.
You need to reaffirm the trust which you have shown earlier and continue with same grit and determination so that you are successful in WAT also.