At this point it's no.
I'm working on a complexe setup and while I'm doing the fronty-end, 2 programmers are working on the back-end within .NET and a dedicate server. This is a big pain as we can NOT import code back in WF. It's not lean for ME. I can not design and push as fast as I want.
For CMS needs ...
In my dreams, I see something with http://wproller.com/. We could work in WF from a template of about 30-50 class (maybe more, I'm not a specialist) pre-setup for the worpdress core.
So basically, it could be possible to program any major web site in days.
NEW YROK TIME
bring it !
All things those site are doable for anyone who master WF. The backend is the missing link at this point.
But of course WF is still amazing to bootstrap
Cheers from Montreal