I'm hoping there will be testers from all skill levels and not just the extreme pros who win tournaments though -- in fact I think there should be some testers who have never tried TM before, especially as Nadeo seems to be trying to draw more people into the game.
I don't want a game that's biased toward a particular group of players (even if that group is the not-so-skilled players like me). I don't think Nadeo wants that either (and they have done a really good job of balance and non-bias in the past). You want feedback from all the different types of people who will buy and play the game, not just those who will be good at it.
And there's always the possibility that some bugs are more likely to present themselves to players who are less skilled as well (say a bug that only happens if you take several minutes longer than the author time on a track, or if you consistently respawn a certain number of times after you've gone off a particular jump block).
I'm sure Nadeo has already considered this, and if they're not doing this there is a good reason for it.
I don't expect to get into any beta test for TM2... I don't expect I'd have the time or the motivation to test as much as they would want me to -- I like my summer job right now, and my primary motivation at the moment is to stay at my best for this job. Honestly I think it would be a bad move to choose me for a beta test. So this isn't an argument for me being in the beta test.
Besides, Nadeo already knows what job I would want with them, and it's not beta tester

.
Like I've said before, I trust Nadeo to come up with a good product, because so far they've proven that they're good at what they do.