On devArt, you have a private storage where you can move your work to, instead of deleting it - it's called "Deviation Storage", and can be accessed by clicking the "Gallery Management" link in your message centre (or by going [here]).

So, if you would like to take down something you submitted for whatever reason, you can quickly remove the work you would like to your storage room - which will seem just like you deleted the pictures, except for one important difference: You can still access it just fine, look at it, the comments, the favourites and everything associated with it, change it, and - if you really want to - put it back on display again, at which point it'll show up again, with everything, from favourites to comments still there.