Everyone seems to have a different understanding of what a "travel planner" is / should do. I was thinking of rome2rio when I read this headline (which is very nice and doing great apparently), but from the comments here I gather many people want to solve the "social" (i.e. what to see etc.) aspect rather than the pure technical one (how to get there, how to save money) of it.
Considering how much money goes into travel (and related mergers/acquisitions - these are real acquisitions and not inflated valuations from 7-8 figure investments), it's definitely not a bad idea though.
I discovered http://www.rome2rio.com a few months back and it's a fantastic site. This is what I was expecting too, it will give me all travel options from point A to B, Google Maps but international/cross border. Maybe something changed on that Yahoo Travel planner, the original article was posted over 2 years ago.
Considering how much money goes into travel (and related mergers/acquisitions - these are real acquisitions and not inflated valuations from 7-8 figure investments), it's definitely not a bad idea though.