Yes, most of the business community still uses IE.
Since
my business is supporting business clients, I have to use what they do.
All of my business clients have servers in their offices, running Sharepoint, Exchange e-mail, SQL Server databases, and various other line of business software packages.
The only product that actually works 100% is IE. With all of the ways people end up with Chrome and Firefox on their computers (software updates from other companies, etc.) they will frequently end up with Chrome. That's when I get the phone calls about things not working.
One of the most important functions that my customers use is the Sharepoint interface so they can remote in and take over their office computer from home. That's called telecommuting. Those functions don't work right in Chrome or Firefox. Unlike products such as GoToMyPC, those capabilities are part of the package and incur no monthly fees to use them.
Of course, Microsoft didn't help themselves by pushing out IE10 as an automatic update, since they don't have IE10 ready for those remote functions either.
And, they didn't help themselves with Windows 8 either, as I think they threw the entire business community under the bus trying to create software that runs on all platforms.
I use IE9 because that's what all of my IT customers use.
MS is ensuring that we are going to have to take them somewhere else, but I haven't decided where yet. Who knows, maybe a whole Linux Server and Desktop setup, although nothing out there is packaged appropriately (yet) for the business community.
I have had a couple of customers attempt to buy in to the idea of Google Docs, and managing their businesses in the Cloud. None of them have been willing to stay there.
For them, like everyone else, the computer is supposed to be a tool, not an obstacle.
Mike's comment about vBulletin is only the tip of the iceberg in business software applications.
Jim