I would say NO.
You have to use the A button (on top) a lot in RE4, which is too awkward when using a gun housing. It does look like a cool gun, though...would be great for rail shooters where you primarily just use the B button (trigger), i.e. RE: Umbrella Chronicles, the upcoming Darkside Chronicles, and the House of the Dead games.
Anyway, the Shot Blaster may or may not be worth it for other games, but will probably not work at all with Resident Evil 4.