Seems to be a whole lot of very emotional, very poorly informed argument going on here, or exactly what I'd expect. It's an interesting case. I'd suggest everyone give the wiki article a read for starters.
Ultimately, this case is going to come down to three things: (1) what evidence is presented; (2) what evidence does the jury find credible; and (3) will the jury correctly apply the facts to the law? Nobody can predict ANY of these things with any certainty.
If I had to guess, I'd say Zimmerman is acquitted, for the simple reason that most of the eyewitnesses to the physical struggle, besides Zimmerman himself, will likely testify that Martin was on top of Zimmerman beating the crap out of him, which appears to be consistent with Zimmerman's injuries, and with the bullet impact.
Whether Zimmerman "profiled" or "stalked" Martin is likely irrelevant to whether Zimmerman ultimately fired his weapon in self defense, at least if the jury correctly follows the law (and there is every indication that the prosecution is aggressively attempting to confuse this issue, which is troubling as a matter of due process). There just doesn't seem to be very strong evidence at all that would negate Zimmerman's argument of self defense beyond a reasonable doubt. Instead, the scant eyewitness evidence would generally seem to support it, but lets see what actually comes out at trial.