Almost every enhancement Google makes to its core product is inevitably now seen through the prism of its intentions to move into vertical areas of search, especially travel.
Google's planned acquisition of airfare data company ITA Software can be blamed for that.
So, assuming for a moment that Google wants to leverage its acquisition for a major consumer-focused play, the data and search technology/expertise obtained through buying ITA is one side of the equation.
But user experience and how such functionality might be used on within search results is something the brainiacs at Google are probably developing themselves.
Live updating of search results (using Ajax or flash) are common on the next generation travel search sites, such as Kayak, Zugu, Momondo, Skyscanner et al.
And it looks like Google has started testing similar web technology...
httpv://www.youtube.com/watch?v=Ty71OxyQKKc
NB: Could not be replicated in the UK.
NB: Hat-tip Andrew Girdwood of BigMouthmedia.