Bingo. A travel planner is pretty much a solved problem. It's called a savvy, experienced travel agent who gives personalized service. The problem, as you say, is that most people aren't willing to pay for that type of service. And it's unclear to what degree software can solve the time-consuming stuff--such as places that aren't online or at least require emailing back and forth or phone calls (as is still the case even in the US with a lot of B&Bs for example). Which is the problem people are looking to solve, given that air reservations and the like are easily handled by existing sites (except when they aren't:-)).