As neat as that is, i don't like it, Mario is shorter and chubbier than Luigi, Mario's hair and mustache is a bit lighter, and Mario's mustache is different than Luigi's mustache
I'm currently working on Mr M, unlike yours which looked like a quick edit, i'm making mine from scratch on top of a picture of Paper Mario, here's a progress picture
(IMG)
The shoes were an annoying pain to do, the M on top was pretty easy, the mask was easy as well, remember, i'm using Paint.net and not Photoshop, so this is gonna be rather tough to do, especially the bandanna that's gotta go around Mario's neck D:
Indeed, it was a quick edit ;)
Also with yours, don't use a soft brush over the original, you can see the slight fuzziness, unlike the rest of the picture that is nice and crisp, unless you plan to paint over the whole thing that is ;)
Edit:I got bored so I drew this;

I didn't like the "full latex" suit so he's still got the blue overalls on ;) and I also used Reguliths advice with the M, it kinda works. Sadly W was already taken ;)