I recently set up a F13 system for my parents, who have been retired for some time and have not used computers at all since their retirement. They had forgotten a shocking amount of stuff (gone from using email to barely being able to find keys on the keyboard). I was dreading a little the handling of photos from their camera and phones, but Shotwell's user interface actually proved to be very easy for them to grasp. Gthumb or any of the other ones would have been a lot harder.
I took a closer look at Shotwell myself and built the new 0.6 version from source. I'd heard about Vala before, but only now realized just what it is. I think it's a great idea to use the C runtime and introduce just a relatively simple compiler and bindings instead of a new VM and an entire runtime. The performance seems to be very snappy (I'm saying this a someone who's been pretty underwhelmed by Mono apps).
I just hope Shotwell 0.6.1 is packaged for F13 soon. There are quite a lot of useful new features.