In my opinion, "AAA" really boils down to "development and marketing budget" -- and this game certainly qualifies.
If you can't consider huge budget, huge marketing, or huge sales, (all three of which this game had) as a definition of "AAA", what do you consider to be the definition? It certainly *isn't* review scores.
This is a AAA game, if ever there was one. If you want to claim its not, you're going to have to explain why.
The "legs" issue is the only outstanding one... at this point, this game needs legs on the Wii in order to stand up to the HD versions. I'm sure its still paying the bills -- the license almost ensures that. But this is a strong indicator for 3rd parties, as to which console to focus on, as a primary, and that could be a concern for Wii owners in the future, with regards to overall game quality.
So far, the legs on the Sports titles do recover some of the ground lost early on, but the Wii never fully recovers in any case, even by the end of the year cycle, at which most sports titles completely die off. The HD platforms always end up looking much more attractive for these titles, from a return % and net income point-of-view.