I have the same question as Dalmatian Hero, and this is the info I've gleaned so far:
-Apple has no plans for software to replace iWeb.
-The current alternatives for Mac users who don't have the sort of mad skillz needed to write code or use Dreamweaver are (a) Sandvox, (b) Freeway, and (c) Rapidweaver, none of which are as good or easy to use as iWeb and which unlike iWeb cost $.
-Last February Rage Software did a big presentation at a big convention announcing a product called Easyweb that's supposed to be an iWeb replacement, and that's pretty much the last anybody's heard of it
If it makes you feel any better, there doesn't seem to be any good wysiwyg editors out there for Windows 8, either. Nothing works with Windows 8.