Not burn-out, but maybe fade-out?

I read a great article on the Carnival of Homeschooling for this week about getting back to basics ("Falling Like Rain") and it really has me thinking. I don't feel I'm burned out, but I do feel like maybe my eldest is a bit. On top of school, he is also in a play and preparing for his black belt test (extra classes and practicing). My middle one really seems to learn more from historic fiction or biographies. Maybe it is time to take her suggested approach of focusing on the basics and letting them select books for other interest areas. I'd want to give them some direction and guidance...just not sure how to go about giving them freedom within a framework. I guess what I need to do is determine what I want the framework to be. Hmmmm....

I hesitate because I don't want to let stuff slide! I'd love to hear from you if you use an approach where you allow your children to determine their studies within a framework (like modified unschooling, maybe?) Like the Newton bio - if he had his way he'd have quit reading it by now, but he'd have missed out on what he learned so far! How do you know when to push and require certain work and when do you let it go? Comments and advice appreciated!