After some tweaking, I got pretty good results from Helicon Focus. I still had to do touchup in Photoshop however. The border of the flower had and odd dark halo around it. Once I figured out how to do it, getting rid of the halo was actually pretty easy.

This reduced size really doesn't do the image justice. The original has enough resolution to print at almost 13"x16" at 300 DPI, even after cropping.