That would be a great idea! A "trip-checker" for hotels, ground transportation, etc.
I love TripIt, but another upgrade I'd love to see would be "to-do" options that could be added for a trip: make a reservation for the dog "resort", stop the mail, reserve restaurants or ground transportation, etc. My work-arounds are to add notes with reminders and dates, and also to use a different to-do app, but it would be nice to have an automatic list to choose from within TripIt.
I have many components of a long trip for next May reserved, but one of my potential accommodations isn't taking reservations for 2017 yet, some train tickets can only be purchased 90 days in advance, and we still need a rental car in one location. TripIt is great for reservations after they are made, but doesn't help with the missing components.