said by Steve :

Protected Mode - "User Account Protection" (run with least privilege) has been the case with Unix for years, but it only protects the *machine*, not *your account*. Malware can easily trash your login settings.

IE7 extends this even more: the main goal of the browser is to render content, and if we can (say) remove access to the filesystem other than temporary internet file

Writes to the user's profile will be automatically redirected to a subdirectory of Temporary Internet Files: this virtualizes the settings, and it applies to things like a Quicktime plugin. No way to delete My Documents from a bogus plugin.

They do allow exceptions (say, saving a Word Template to your templates directory), but it prompts the user. This is handled by brokers that do the elevated-priv stuff, and it guards access carefully.

There is a whole Integrity Control layer that sits between IE and the system, and it looks really well thought out - it's very comprehensive.

said by Tuulilapsi :

Now this sounds interesting, and promising.

Thank you for posting this. Very, very interesting stuff.