A new Microsoft browser?

Whereas I would really like IE not to do that, and ideally Firefox and Chrome to move to longer cycles (minimum 6 months, preferably annual) for their main public releases.

One good reason for this is that there is no point in having browsers support new features within moments of someone conceiving them unless developers are also keeping up with new developments at the same pace. Take three major browsers on a six-weekly cycle and you literally need to be updating your skill set every two weeks and have projects to work on where those new skills are actually useful. Unless all you do is write trendy web development blogs for a living, you are not likely to be in this category.

Another good reason is that both Firefox and Chrome have horrible records for quality since going to six-weekly release cycles, both in terms of bugs/regressions and because they frequently implement new features that tick boxes but have such poor quality of implementation that they aren't actually useful for production work anyway. For example, right now, both Firefox and Chrome have numerous glitches and performance problems in popular HTML/CSS features like animations, web fonts, multimedia elements, and SVG, to the extent that you can't reliably assume even relatively simple applications will work without extensive and ongoing testing.

Recent versions of IE stand in sharp contrast to that pattern, and as such I think IE now provides both a valuable brake on the industry and a demonstration that having a solid, fast implementation of some features is far more useful in practice than having unreliable and/or slow implementations of more features.

(Edit: It's disappointing to see multiple downvotes yet no responses. This happens all too often when I express the unpopular-but-based-on-hard-data view that Firefox and Chrome are often slow and/or buggy when it comes to new features, even though numerous articles and blog posts giving specific examples in the areas I mentioned are yours to read for the price of a Google search.)

Or possibly because the API's microsoft proposes are pretty horrible; I've worked on FF and chrome extensions, and I investigated IE support - but IE's extension model is truly terrible. Just take a look at that stackoverflow link you posted. What a mess. I wouldn't mind a clean C++ or .NET api, but the current API certainly isn't that.

If IE is there primarily to access the corporate intranet and other work-related sites, as usually seems to be the case in this kind of environment, then that stability is a feature, not a bug.

The last thing you need as a sysadmin for an organisation with thousands of members is someone who thinks they know better "upgrading" their browser to a new version that no longer works properly with critical business sites/apps, has unknown or at least untested-by-IT security issues that therefore may or may not require mitigation at corporate tooling level, and so on. This is particularly true if, as almost invariably seems to be the case, that individual won't be the person who takes the flak when something breaks, violates regulatory compliance, creates a security problem, etc.

I doubt there is a single organisation anywhere in the world that has IE locked down at corporate level, yet where any legitimate business purpose would be better served by having browser software updated every few weeks.