The thing is, from a programmer's perspective I actually think the generic "Tiling" approach is actually a smart improvement upon the ad hoc gadget approach to putting things on the desktop.
It seems to me it's much more maintainable and sustainable in the sense that it offers a clean way to put stuff on the screen in a way that trying to support arbitrarily shaped and sized gadgets is not. It's a good example of choosing a simpler more reliable and maintainable solution over allowing everything under the sun. And those simple-looking solid color tiles, again it's just a cleaner solution that suggest easier programming and UI consistency.
My major complaint against what Microsoft is doing is about their decision to make it so hard and confusing to switch between this tiled stuff and desktop view without these gadgets, and how ill-suited this approach is for a large start menu hierarchy, etc.
I think a much smarter approach would have been to leave the original taskbar, startmenu, system tray -- which to my way of thinking are excellent, and simply replace desktop icons with the tiling system, with a simple way to toggle tiles off to yield a blank desktop (or switch between tile sets); to me this would have been so much better than the confusing approach they have come up.
I can only hope they will realize that this tile/gadget/ipad/touch layout is only suitable for certain workflows, and make it more natural and intuitive to switch modes of operation.