If you need anecdotal evidence why Opera or other alternative browsers should be allowed to be installed and/or installed by blanket policy, I gots that too!
I'm the IT director for rapid appraisal, inc (http://www.rapidapprasial.com), and I had a problem that was easily solved with Mozilla.. but this can be used to push _ANY_ alternative browser..
Two weeks ago a co-worker of mine accidentally clicked a link !off of www.yahoo.com! and, without confirmations or any notice whatsoever, infected our entire terminal server. 6hrs, a company-wide bitch-session, and a pot o' joe later, termsvr was clean and SANS-I.E.!! Any of our sites that require IE were created as shortcuts - "iexplore.exe http://foo/bar.asp".
I have now seen a 20% reduction in memory usage and a 60% reduction in CPU. IE is horribly inefficient. and also, popups are no longer an issue! yay!
oh and no relapses.
The infection pathogen was MySearch bar and it's outlook parasite, one of the harder bugs to get rid of.
all casual surfing and research in terminal services is now done using an alternative browser under penalties of i revoke their access if i catch anyone in IE for anything other than sites I've approved. and i watch histories.
There ya go, tell that to your it guy. If necessary hes more than welcome to email me via my blog.
Public Service Announcement: DO NOT USE INTERNET EXPLORER!!!! Definition: MySpace [Mai' thpathe] (pronounced with a lithp), N. - 1. A shrine to Terrible teener web programming, the worst M$ driven Web2.sl0 has to offer.