Well, with both Chrome and Firefox on rapid mandatory release schedules, all I can say is: Get comfortable supporting IE for large enterprise customers forever.
Interesting... I've been consulting for one of the biggest of the biggest you could dream of.
There's a tendency which you may have heard of: mobile (smartphones and tablets) and there's a lot of push for making these supported and available to employees (the push very often coming both from the employees and from very high up the chain).
As a result mobile browsers support in large enterprise are becoming very often mandatory.
Why do you think large enterprise are supporting browsers at all? why do you think large enterprise are switching en masse to internal webapps instead of internal desktop apps? To free themselves from a particular technology vendor. It's the way they regain control. And you think they'd ruin all that by mandating "IE only"!?
This is not at all what I'm seeing in the enterprisey webapp world. On the contrary: the shift is to more platform, more standards, more openness.
