Hey bilash,
Getting 850 is no big deal. Aim for the stars and you shall get what you had set out for.
Oh and btw, this is a small piece of advice for all the prospective Fall '06 CS appers. There's absolutely no need to go ga-ga over your AGRE results. The AGRE is small part of your overall application and in most cases, doesn't have any significant impact on the probability of getting admitted to a particular school. Therefore, there's no need to be dissapointed if you ended up in the 600s and the 700s (which by the way, is a pretty good score).
With that out of the way, good luck to everyone!