Develop their own "vacation planner" service such as what Larry just described - maybe confine it to just one kind of vacation holiday to make it more manageable.
A vacation planner is the very tip of a giant iceberg. Depending on the trip, a system simply cannot be conceived. Outside the US, specially in not so stable countries -like emerging economies- conditions are such that most trips may require local assistance in the form of a local agent. I just completed a trip for a foreign couple that would be driving the northern region of a south american country for 30 days, staying in 19 hotels. Just imagine the long distance calls, transferring of funds for downpayments, etc.
A trip like this could easily take months in the planning with questions and changes going back and forth. This one started 8 months ago and my files already accumulated 300 pages. Last email I exchanged was over 1500 words answering inquiries regarding vouchers that implied tax payments on a car rental. No system can answer this. Not even get close to the demands of travelers who now come armed with internet information.
A vacation planner as the one we have on our website is just an initial step in a long, detailed dialogue that will follow. What comes next is a blank page with infinite posibilities... Trips that may become so dynamic that will change by the day according to new input. Input that goes from unanticipated changes that happen at destination to tips of where to change foreign currency in the black market upon arrival. Something that even a local agent may need to re-discover.
Now, if someone only wants to go to Orlando for 3 days... that maybe the equivalent of simple, straightforward searches with "basic" intent. As opposed to wanting to "explore strange new worlds to boldly go where no man has gone before".