Farecast had a very different UI when MS bought them. The transition to the copy of the Kayak UI happened well after Kayak rolled theirs out and also well after MS bought Farecast.
The scenario/timeline you outline above is reasonable enough to assume - as is the idea that, as Farecast came out before Kayak, that Kayak was actually copying Farecast. What actually happened though is different. Farecast had a completely different model - they were banking on their ability to forecast whether or not you were likely to get a cheaper fare for the same route if you waited. Their original UI was based around that idea and it didn't go over incredibly well. After the Microsoft purchase and before the launch of Bing Travel they did a major redesign and got rid of most of the old Farecast. The old Farecast price predictor idea is reduced to one line at the top of the flights list on the page center.
I wrote about this and posted to HN shortly after Bing Travel went live and because of that I've been introduced to more information about the whole situation than I had when I originally brought it up. In a nutshell, the Microsoft team blatantly copied Kayak's UI and has pretty much gotten away with it.
The scenario/timeline you outline above is reasonable enough to assume - as is the idea that, as Farecast came out before Kayak, that Kayak was actually copying Farecast. What actually happened though is different. Farecast had a completely different model - they were banking on their ability to forecast whether or not you were likely to get a cheaper fare for the same route if you waited. Their original UI was based around that idea and it didn't go over incredibly well. After the Microsoft purchase and before the launch of Bing Travel they did a major redesign and got rid of most of the old Farecast. The old Farecast price predictor idea is reduced to one line at the top of the flights list on the page center.
I wrote about this and posted to HN shortly after Bing Travel went live and because of that I've been introduced to more information about the whole situation than I had when I originally brought it up. In a nutshell, the Microsoft team blatantly copied Kayak's UI and has pretty much gotten away with it.