<<Since the launch of the developer sandbox, many of you have asked when the new features of iGoogle will find their way into users' hands. We plan to release canvas view and the new interface first, sometime in June. Those of you with existing applications should add a canvas view to take advantage of more screen real estate. And using canvas view, you can also monetize with ads.>>
http://igoogledeveloper.blogspot.com/2008/05/igoogle-roadmap.html

"you can also monetize with ads" => good way to fill Google Homepage with ads... :-/