The thing is, Microsoft has gotten in trouble many times for the numbers they claim to investors. There's been times where they claim a number, then backpeddle and say "We were counting replaced systems as well." there are other times where they say "We were counting shipped units as sold units." this happens all the time.
It's not as bad as Sony saying "We've outsold everyone in our class!" then when he's called on it, he says "Well those other systems aren't in the same class as us, we're higher end." They fired that guy.
And as for being serious about the poll, as a consumer who has purchased 6 X-Box 360's, 3 of which have failed, 2 of which can't fail cause they're the new design, and 2 of the 3 which failed have been replaced, and 1 failed again, yes. I believe 50% of the systems fail.