in response to

> Maybe another way to do it is to put it in babel. English writers don't
> really need T1 fonts, and don't need a change in latex2e right now. But
> any language in babel could have a default inputenc and fontenc, such
> that setting
>
>         \usepackage[francais]{babel}
>
> or (german, or any west europe language) would automatically set the T1
> fontenc and the latin1 inputenc. Setting
>
>         \usepackage[russian]{babel}
>
> would select a different and suitable (inputenc,fontenc) tupple.

and a french commentary on a russian text would... ?

it's not as simple as you imagine (not least because the inputenc side
of things is so complicated for russian).

denis roegel brought this idea up in pr babel/3046, and there's a
pretty clear response from johannes in the database (the response
actually appeared this week, and _is_ in the database -- i've just
checked).

http://www.Uni-Mainz.DE/cgi-bin/ltxbugs2html?pr=babel/3046