To be fair they encourage people to upgrade from MSIE 6 and 7 too, and if they can achieve that, I'm willing to consider that a good thing.
But still, kind of a dick move. The whole "get lost" message isn't really a good marketing move either.
I guess not. I use FF 3.0.x and they said "old Fire Fox". It looks like many people are actually downloading IE8 to participate in this. Hopefully, this actually may not change the market share of IE vis-a-vis its competitors. If you are an FF user, even if you download IE8 and participate in this contest, you are most likely to stick to FF. IOW I'm hoping that the downloads won't actually translate to conversions from other browsers. One good thing that might come out of this is some IE6 upgrades to IE8.