This week's giveaway is in the EJB and other Java EE Technologies forum. We're giving away four copies of EJB 3 in Action and have Debu Panda, Reza Rahman, Ryan Cuprak, and Michael Remijan on-line! See this thread for details.
Unless the PrimeFaces and RichFaces teams explicitly say so, I'd be very reluctant to mix PF and RF even in the same application, much less on the same page.
There are some extension tagsets that can be mixed and matched with impunity, but the more complex ones often do their magic by tapping deep into JSF's internal operations and sometimes they both want to tap the same resource, but do so in conflicting ways. Periodically, JSF adds improvements designed to minimize the need to do this sort of stuff (or at least co-ordinate it), but it's a bit of a gamble if no one is willing to certify it.
Customer surveys are for companies who didn't pay proper attention to begin with.