The way I interpret this (and I have been wrong before... I think it was a Tuesday)...
By providing the answer ON THE RESULTS PAGE, it captures all of the marketing potential of that web search. In other words, people will not traipse from web site to web site full of irrelevent drivel, all the while being exposed to the marketing included within those irrelevent sites. Naturally, this increases the value of advertisements on Bing, due to the fact that it is reducing the chance that users will proceed to other sites.
Synopsis, this is yet another round of increasing the advertising share. It is driven by money. Help you make better decisions??? Puh-leeeze!
With all of that being said, I conceed that it might very well result in a faster set of answers for the surfer. Time will tell.
More importantly, how long will it take before the common vernacular "I think I will Google it", is transformed into "I think I will Bing it". I mean, lets face it, you NEVER hear someone say "I think I will Yahoo it", and that search engine has been around forever.
Can you Bing it?