The Yahoo! Design Preview became available earlier this week. Since then folks have been testing it out. One thread at WebmasterWorld notes that if you are testing the new design (more on that here) and if you go to Yahoo! Travel you will notice the search box is already filtered to show segmented results for travel search.
After you conduct a search, the results come from "Yahoo! Travel Guides."
It seems to me, that this was also implemented at the normal, non preview, Yahoo! Travel section. I am not sure if it is exactly new - but it is interesting to point out, nevertheless.
Forum discussion at WebmasterWorld.