there's nothing technically wrong with this photo
the catch I see is that tree scene would easily be a larger photo cropped down if one didn't know better. it doesn't scream "panorama"
from experience with panoramas you need something to focus on in the photo for them to work well and with a panorama, you really want more than one good subject/area of the photo to make it even better. I also find a panorama makes a better statement when you know when looking at it that you can see multiple directions at once but this isn't required.
for example, this photo is one of my favorites. multiple directions, obvious subject (made using auto stitch from probably 5-7 photos
Curved View on Flickr - Photo Sharing!