OK, first of all, "GangstaLawya" seems to not be taking into account the fine work of Kepler, Newton, and Einstein when he suggests that we "remain agnostic" on the issue of heliocentrism. True, Copernicus himself does not excactly refute Ptolemy here (he actually was more worried about how other astronomers and Protestant theologians would react to his heliocentric system than how the Catholic church would see it... and his model wasn't fully accepted until over a hundred years after his death), but this model was later augmented by Kepler and Newton to the point where it does work better than Ptolemy's. And with all due respect, the Ptolmaic system is extremely convoluted, needlessly complicated, and downright ugly at times... so even if there's a simpler way of looking at things that works just as well, that's still a conceptial improvement. Occam's razor, y'know?
But I digress. As with most of my reviews of books like this, my concern isn't necessarily the actual book (which is usually self-evidently worthwhile), but with the presentation. I must say that it's a little awkward to see Stephen Hawking's name appear on the cover in larger type than Copernicus' and not get anything more than a very short introduction by him that doesn't say very much. In fact, there is not very much of a difference between this edition and the one published by Prometheus Books; the text is exactly the same and contains all the same diagrams. The cover is flashier (and says "Stephen Hawking!") and the type is cleaner. That's it. Those are the only real differences. In fact, the only reason I can see for this edition existing is Running Press (and Stephen Hawking) making a few bucks.
Despite all this, there isn't really anything here that detracts from the work. So basically, you can buy this copy or the Prometheus Books edtion and it won't matter; you'll get pretty much the same thing and pay pretty much the same price either way. I'll leave it up to you whether you want the flashy cover (complete with Stephen Hawking's name on it) or the plain one because that's really about as deep as the choice goes.