personally, i think this could be very funny, BUT, i can't honestly see it extending for even 30 minutes. i've been on stage most of my life, both in front of and behind the scenes and i can tell you that unless you have extremely good material, you will lose your audience after only a few minutes. i have to agree with sysadmin here and say that 5 minutes is about all you'd be able to realistically do, in my opinion.
now, that said, i'd love to see it. i was doing comedy of errors by Shakespeare a number of years ago and at one point, one of the characters has an exorcism performed on him. at our first rehearsal, when we performed that scene, the person playing the priest who performs the exorcism dropped into a southern baptist televangelist accent and gave his line "i cast the out vile demon". needless to say, everyone cracked up laughing because it was so well done and over the top funny. however, while it was funny the first time, it would not have been so during the actual performance and the director required the lines be read properly.
if we think about it, while that one line was funny, if the actor had tried to perform the rest of his lines with the same accent, the part would have gone from being funny to offensive very quickly. the whole "he's trying too hard to be funny for the sake of being funny, and it's obvious, and because of that, it's not funny (aka tom green/jackass)" thing. this idea has that same potential and it would be very difficult to not run into it. keeping it very short, like a commercial, would reduce the chances of that but your material would still need to be top notch and writing even 5 minutes of comedy is not easy.