It's had a good start because of all the hype and advertising, whether that actually continues after the initial marketing is finished will be another matter. It really depends on whether the general public like it or not , Webmasters can think what they like about it and it wont matter too much , its the general public that really matter.
what i like in bing... when you search some images... there are more relevant results than the other Search engine... in other SE there are more irrelevant images than relevant
Actually, Bing originally from the name MSN Live so why asking for the season of its growing thing besides they just change name and just renovated the site to make it more new to the public viewers.
It is because of massive promotion. Massive backlinks. And Moreover, THE HAND OF MICROSOFT OVER BING.COM.
Bing is the "hot topic" of the day and a fad. Its nothing but live search renamed with almost no new options. One of the reasons why its so popular is because of the TV advertising. People see it on TV and think "oh cool". With enough money and enough advertising you can make a dead dog popular.