Hullo, Stephen,
You beat me to the posting of the fact that there is a first review of DESOLATION up on RPGnet, but that's all right, as it should be the folks from GMD who post about this first!
That said, the review is pretty much positive, but I find it interesting in terms of the element of darkness that the game has, as implied by the review. Post-apocalyptic settings, regardless of whether they are sf or fantasy, tend to have a darker view regardless, but I suspect in the case of DESOLATION one can run the game as dark or as lightly as one chooses, although too light a game might spoil the atmosphere of the world of DESOLATION. In my mind, the question arises as to whether one takes a horrific or non-horrific approach to this as well, and I could easily see more Lovecraftian, Phil Dick-style, or even Vonnegut-style games.
The other element, that not all GMs are going to be able to pull this off, or even run the world of DESOLATION well, is something that I think is up to the indivdiual GM. The Ubiquity game mechanics and dice system actually help reduce the problem somewhat, as the game system is relatively simple, and combat is fast and furious when it is handled right. Having the "feel" for the game world is something that I think bears more discussion, to be sure.