We all know there are problems with X. We know that the abstraction between client and server does not suite all types of application and can be an apparent performance barrier.
BUT (and this is a big but)
If you know X, and work in an environment with many networked systems all of which understand X, then the benefits of the abstraction are HUGE. Don't suggest that VNC can fill the gap, because unless you have a big fat network, the performance is crap compared to properly written X apps. If you've not worked in such an environment, you may not know this, but your view risks throwing the baby out with the bath water.
One of the problems as I see it is that because the font handling in X was based on the fonts that the server know about, rather than the fonts that a client wanted to use, some applications appeared to display poorly. To get round this, both KDE and Gnome introduced models that meant that font glyphs were effectively loaded by each client when the client started, often multiple times.
This increased the X server memory footprint and client startup time no end, and almost completely broke the efficient font model that X had (and still has!). In my view, the best way of handling non-standard fonts is to have a font server somewhere (either locally or on the network) and have a mechanism for font-picky applications to add the FreeType or Type1 scalable fonts to that server, either for the duration of the run, or permanently.
Similarly, the way that some application treat pixmaps (and Java is one of the worst culprits, wanting to do it's own graphic abstraction) mean that X performance is much worse than it needs to be for such apps.
X.org is making what I think is a very sensible move to OpenGL based rendering, especially if it has network abstraction built in (I've not checked). This should allow good 3D performance, and as we can see allows the gloss to be added. What we need now is a well recognised, resource controlled window manager and application framework. Whether this is Gnome or KDE, or something completely different remains to be seen, but introducing a new default must be backed up by allowing users who want to remain with what they like to do so.
I actually cannot stand the netbook remixes, even on systems with small screens. They are just too proscriptive, and just get in the way unless all you want to do is what they provide. I use Gnome on my EeePC 701 (800x480), and I only have a small number of times when windows fall off the screen, so I don't see the need for the netbook remix.