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The 'wall' should really come in a 2x2 configuration by default, not just as an option. I really don't see the point of putting them on a line as shown in the Beryl video, wasting all that space and showing them so small. Here is the same effect on a 2x2 configuration (on OS X):
As for the wheel window switcher, is that really a *good* example of usability? I find it about as useful (that is, not much) as Vista's: some windows are partially covered by others. Basically, just like the wobbling FX used every time a window moves or opens (*), that particular video screams "look at what I can do" more than "Beryl Usability", at least to me.
(*) How is wobbling anything (windows, drop-down menus, even freakin'tooltips!) a good thing, from a usability point of view?