Well, I did think a request forum would be useless mostly because I was thinking about N56, SNES, etc and assuming that if anyone had the box they would have already scanned it. Thus, as Valeman says, requesting a cover is like asking someone else to buy/supply the box.
However, for current-gen games someone might have the game and just not bothered scanning it or something (this could happen for older games, too, I suppose). Then the request thing makes more sense.
Personally, I'd love to see some scans for games that lots of you probably have, like FFX and Baldur's Gate: Dark Alliance for PS2, just so I can replace my Greatest Hits versions with the original covers.