[Silhouette]

The problems you mention are certainly real, but are they problems with hover effects in general or with specific uses of hover effects that may not be appropriate?

For example, while I completely agree that nested hover menus implemented naively (as many sites do) can be very annoying, single-tier menus with large areas can be an effective way to provide navigation of larger sites without cluttering the main page with dozens of links that most users won't care about. Likewise, while the "falling off the edge" problem is a real one, there are tools like jQuery's hoverIntent plug-in that can make the UI feel much more natural.