Seems a bit soft and the blacks of the trees are not quite silhouetted on the screen I am on. I will make sure to look at this one again on my other monitor before rollover, just to be fair.
Added: Looks better on my usual monitor, though it still seems a bit soft on the details.
Levels can be a useful adjustment to make sure that a silhouette shows as such. Just clip the low end of your histogram a little and that will ensure it is all black and not a range of dark grey, almost-blacks.
This shot would be more interesting if you had the sun peeking through the trees, and made the sun more of a defining aspect of your photo. Seems like you might've barely missed the perfect timing for the photo.
Some silhouetted trees and a hardly purple sky...Sorry, but there's nothing particularly attractive here. Could work with a more graphical silhouette IMO, a very special or big tree, or trees in line...