> 
> 1. IFRAME element needs to be added to HTML Strict. Currently
> even fully conformant web-sites have to use HTML Loose or cheat

The fundamental conflict between frames and the "web" concept
(inability to hyperlink the state of a frameset) also applies to
iframes.

> on validator, because IFRAME is an integral part of too many
> solutions. I guess the Transitional phase is well passed :-),

The transition is not passed because major browsers still do
not fully implement CSS2.