Ah yes, the "creaky old IT department"... Gosh darn it, if it weren't for those old fogies and their weird inclination to worry about making sure things actually work, and their bizarre insistence of mapping technological choices to the strategic concerns of the business (as opposed to just providing the coolest new toys for all the geeks to play with) - then, we might actually be able to get something done!
Maybe what we need is a general strike. Have every app go dark for these old browsers on January 1st 2014 for one hour a day. Then double it every day until its 24/7.
If they can deal with Y2K, they can deal with something this trivial.
Of course, its those creaky old IT departments.
Stop catering to these old browsers and people who want your app will download a capable browser or pressure their IT or just use their phone.