The current plan is to go to Prague as part of our "Iron Curtain" trip, tentatively scheduled for the fall (when it's cooler here - since many of the Eastern Bloc countries don't have consistent air conditioning). That may be pushed to Spring based on Katie's school schedule, though.
Prague was originally high on my list until I realized it had become a popular tourist spot. We're still going to stop there, for sure, but I think we'll make it quick. Rumor has it that it's beautiful, but has also become a party town chock full of drunk foreignors.