What about the regular cover (which incidentally, I nominated)?
It's a little better I think. The problem is though that neither really stands out as a cover per say. There really isn't something that would make them stand out from any other cover at my LCS and that's an important factor in judging whether a cover is good or not. They make it clear what is going on inside, and that's an important thing, a problem WAY too many covers have these days. I'm more than a little sick and tired of searching through my back issues trying to find a particular story and getting no help from the covers themselves at all.
Both of those covers need something and I'm not sure what, but it's more than just producing something that looks like it could be a panel inside the comics. Take this classic cover as an example:
It's not as complex as the Northstar wedding issue's cover, but there's something about it that seems like a better cover. It's simple, but the heart shaped spider symbol in behind Peter and Mary-Jane, combined with their poses seems to be more interesting than Northstar and his husband. I think in the end the problem with the two Astonishing X-Men covers is that they're too busy to be really good covers. There's just way too much going on in the background and it's a distraction from what should be the sole focal point of the cover. A good cover is simple, but still finds a way to get the point across in a dynamic way.