Creative Suite is decently integrated (as long as you stay consistent within the version numbers, importing older projects into newer versions has a nasty tendency to make them no longer backwards compatible unless you specifically re-save as the old version) and there are already plugins that support converting Ai (Illustration) into Canvas (http://blogs.msdn.com/b/mswanson/archive/2010/10/12/adobe-il...). From Adobe's perspective as long as they can keep a tight grip on the authoring tools market (where they actually make money) they are better off hedging their bets.

Photoshop and Illustrator are still the gold standards within the web/design community and while not loved by everyone Flash/Flex is still a very popular platform for developing rich applications. The more Adobe can do to move Flash/Flex (the authoring tools) from being tied to the actual Flash plugin, the better it is for them in the long run.