It has been on my list of Ideas to post - just been slow -
we have several times a week that people want to do that type of transfer - many times when people are moving blogs, either between WordPress.COM blogs or they are moving to a .ORG install and want to make sure that none of their pictures are lost.
I would use that feature with my captnmike.com site since the pictures on it go back several years, the pictures are were on at least three different computers and I think I have them backed up on an external drive. But as I found out this spring finding individual files out of literally over 1,000,000 files sucks.
Then add the mobile posting from your cell phone with the WordPress App and the case I think gets stronger.
Don't forget just the piece of mind having the pictures on a few CD's.
I would bet a couple of stale soggy slices of Pizza (shipping seems to take a lot out of Pizza) or a couple of my handmade captnmike handmade key fobs (they ship better) - that it would be a greatly appreciated feature.