The support for Wicket is close to being on par with the support for JSF. You do loss some of the utility components that you have with JSF (as those just take time to realize), but you get all the core features of Seam (bijection, events, conversations, etc). Despite Seam's commitment to JSF, I get the impression that Wicket is going to receive equal attention in the future.
Congratulations for putting so much energy in your book!