To Miss Piggy;
Mo-speed does pay Canadian taxes, since he is NOT an American citizen. My brother is a dual citizen and he pays both (lived in the US for 20 years). Secondly, It is up to the Canadian government to determine whether he is Canadian, fortunately your opinion does not matter.
Getting back to MO and his accomplishments. Running 12.47 off a PR/PB of 3.39 for 1500m says either he is doping (a typical LR response to this situation, a la Radcliffe, etc.) or that he is maxing his ability at this distance despite his apparent lack of speed (hence the moniker Mo-speed). It shows that others with better relative speed who also max their abilities (such as Bekele) are likely to run faster (like 12.37). I think it is safe to assume that Bekele could have run even faster if perhaps he had the consistent coaching as had Mo under Jerry S. for the past number of years. He was a product more of ability than training per se.
Also, that I see Justyn Knight similarly getting down to Mo's level in a number of years, since he is faster than Mo, assuming that he can stay healthy and is committed to a good 5 years more of training in order to progress and make up for his lack of training background.
At one point a number of years ago I thought that Mo (like Bairu had done) might move up to the marathon. Seems like a good decision to NOT have made that transition at this point.
Speaking to Mo at an awards banquet a few years ago, I was impressed that he was not in this to merely be a Canadian champion or record-holder, but that being amongst the best in the world was his reason for doing this sport. I told him that this was a great attitude (see Houlihan and her goals for reference) and is partly why he has succeeded where others (nameless) seemed satisfied with being a big fish in a small pond (either CIS or NCAA or just Nationally), and failed to progress to the levels of their ability. I have seen a number of top class athletes and am often galled at those who profess to be serious but push comes to shove don't seem to have the persistence to follow through to maximize their potential.