actually, we do have a few designs that would be capable of deflecting an asteroid provided that we had enough warning (which we do with Apophis). The simplest and design and the most likely to succeed is the "gravitational tractor" method which basically involves hovering a spacecraft near the asteroid for a long time but never letting it touch the asteroid. After a few months or years, the mutual gravitational attraction between the spacecraft and the asteroid would pull the latter out of its orbit and into a new one. Since the first chance for Apophis to hit us is in 2029, we would have more than enough time to deflect its orbit by the small amount that would be required. But I think that any action now is very premature we still don't know for sure if its going to come close to us at all. The asteroid is only about 750 feet across and its a hell of a long way away so we don't even have a 100% sure orbit solution. However, in 2013 it will come within 0.096 AU or about 14 million km and we will be able to get some radar measurements to find out for sure what its orbit is.
We currently have 20 years to figure out something to do about it if it does turn out its got our name on it and we already have a few ideas that are practically sure to work. Given this, I don't think waiting another three years to find out its orbit better would be a bad idea. Especially because there is the very real possibility of making a mistake if we start doing sh*t with it before we actually know what its orbit is. Wouldn't it be great to make an adjustment only to find out that it wasn't going to hit us before but now it is? some heads would roll for sure...
Also, just for the record: Despite what the movies show, blowing up anything heading our way with a nuke is not going to happen unless we somehow miss seeing the object until the last possible moment. To try to explain why nuking an asteroid is a bad idea, imagine that someone throws a chunk of rock at you and you try to not get hit. Which would be easier, dodging the rock or shooting it and then trying to dodge the thousands of smaller pieces of rock that result?
Not trying to be a fanboy. Of course, it's hard when you own the best console eve... dang it
