HTML5 Little thought: legacy template

Question came from the presentation of @codepo8:

using html5 sensibly
audio and video (video is 'coming soon')

His idea: How about moving  IE < 9 fixes to server-side? Padding with DIVs with classes and no JS for IE?

If think with Responsive Web Design...

The Idea will be: make responsive web design more responsive with legacy web browser.

The reason: even JS patch works, still, legacy browsers are too problematics to developers. (e.g. the speed, DOM incompatibility, etc)

Idea is here but the implementation is problem...may be similar to mobile template (lets call it legacy template), with much more inaccuracy. Also it may be suffer from the problem of versioning again.

IE, please die. Old version of modern browsers, please rest.