The fellow over at pickup truck talk gave a good, and somewhat unbiased, overview of the issue:
He didn't really give an opinion one way or the other, but rather just laid out the story and GM's response, as much as possible.
I will say, even though I think the Colorado is a decent contribution to the midsized segment, I have some doubts/skepticism regarding GM's handling of the situation.
1) There is no proof that this guys was romping on the truck...conversely there is no proof that he was driving at a reasonable speed while towing that weight. But for all of the internet experts, and GM experts, to say that this whole thing was the result of owner abuse without presenting any supporting evidence is just a classic case of defensive/myopic posturing.
2) GM's official claims about 1" bigger tire size and 100lbs over tongue weight are a bit ridiculous. I don't see how slightly larger tires would play any role in this issue. 100lbs over tongue weight is over OEM recommendations, plain and simple, but if it only takes that much excess weight to cause a catastrophic failure of the frame, I question the OEM's design.
3) Speaking of OEM ratings, GM does not provide a max tongue weight rating. It does state that the tongue weight should be 10-15% of the loaded trailer weight. With this guy's trailer weight, that should be about 210-315lbs...seems excessively low no? As well, any trailer over over 2k lbs is supposed to be equipped with integrated brakes....again seems like an excessive restriction on GM's part. As well, the ZR2's GCWR is lower compared to the regular Colorado, by about 1.7k lbs. By comparison, the Tacoma (w/ tow package) has a max tongue weight of ~640lbs, has no restrictions regarding integrated trailer brakes and engineers its most offroad-worthy trim (TRD Pro) to have the same GCWR, GVWR as its base versions.
It kind of seems like either GM had to make deliberate durability compromises to the ZR2 in order to gain the offroad performance or that the Colorado design is inherently limited. Not explicitly stating a max tongue weight rating and requiring integrated trailer brakes for any trailer over 2k lbs just smells like corner-cutting to me....which is sad, because otherwise the ZR2 seems like an awesome truck. And using slightly bigger tires and slightly over-spec tongue weight as excuses to deny warranty is just foolish on GM's part...those sort of actions don't inspire confidence on the consumer's part.