There are three dimensions to local: "where I am," "where I'm going" and "where can I buy it?" The new Yahoo! Trip Planner seeks to leverage a number of Yahoo!'s locally oriented applications and information, including search, maps and user-generated content (ratings/reviews). The app also lets users share their trips with others (per Yahoo!'s overall FUSE/community strategy).
That aspect of things is perhaps the most interesting. I can see, hypothetically, where others have gone before and discover places to stay, etc., that I might not otherwise have known about. Watch out TripAdvisor.
This appears, in my cursory overview/instant analysis, to be a really nice packaging of existing tools on Yahoo! (sort of like an art museum presenting elements of its permanent collection in an interesting and fresh way).
The Yahoo! blog has more.