Personally I prefer to not have the ability to move files while they are being downloaded, that way I know the full download goes to one location rather than chancing the download being split and missing some of it.
I did say that it was my opinion.
If this is added, I'll probably never use it. Heck, for most of my DCC transfers the transfer dialog is minimized and closes automatically, thus I don't see the buttons at any time now anyways.