Ideally, a user should not have to hover over something to know whether it is clickable. It is a designer's responsibility to make sure that a user can scan the page and know exactly what parts are clickable, so the user can quickly perform his or her desired action.
Ideally, yes, i agree with you. But when the site's users are not necessarily computer litterate, a few hints can prove helpful (sometimes it is also a designers responsibility to take people gently where they have to go). And for some playful designs, rich on graphics and taking the conventions a bit further, it can be complicated. <br>
Hover also works as a confirmation: mouse pointers turning into a finger, that means 'yes, click'. This has been conventional for a very longtime, and it works. Watching touchscreen users tapping blindly on their ipad, checking what works and what doesn't, will probably become a frequent spectacle :)<br>
But you know what would really annoy me with the disapprearance of hover? It's slightly like the bit.ly scenario, only worse, and it's unrelated to css or submenus: The mouse over a link have since ages showed the link's url. A reasonable part of the website-reading process is made of avoiding bad or irrelevant links, not speaking of nastyspamsite.com/fakeapp.exe addresses, and hovering hover links is capital. How do we do this on a touchscreen?
