Another thing I already find quite upsetting is the tendency to use right aligned "floating" tables. What is the use of this? It disociates the table from the page, making it much more difficult for an alternate rendering agent to determine where to put it (when to read it out aloud, for instance).
Okay, I notice I'm getting myself worked up here, so I'll stop. But please, can't you all see that this is the road to disaster?
I second the comment on right-aligned tables. They force content that flows to the left of the table to be far too narrow to read -- unless one widens the entire window, and then the full-width content is too wide to read comfortably.
Tables should be within the flow as a block in their own right, likewise images.
I'm tempted to add "powerpoint slide" to the "what wikipedia is not" page ... :-)