There will still be methods of determining whether the browser is IE or not; that's virtually impossible to hide. It will require a little more effort, but ever

There will still be methods of determining whether the browser is IE or not; that's virtually impossible to hide. It will require a little more effort, but every browser is full of tell-tale bugs and other implementation nuances that can be used to uniquely identify it. It could even be as easy as detecting support for CSS vendor prefixes or similar.