18-odd months ago wrote Haochi in this forum (now-locked thread):
http://blogoscoped.com/forum/75386.html

# New Feature in Gmail: Mute Thread
  
# Friday, November 10, 2006
# 1 year ago • 434 views

"Theres a new feature (really new) in Gmail that Google doesnt want us to know about, though they just have updated the whats new page last night.
The new feature is called Mute Thread, or Mute for short.
If you subscribed to a mailing list, and you want to Archive the message, make it disappear from the Inbox. [...]"

That concerned the full-AJAX-y 2.0 view. I use exclusively Basic HTML view, where --I am pretty sure of that-- until today or yesterday, that "Mute" function was absent. Now it is present in the "More Actions..." drop menu in the Inbox, Starred, and Sent Mail (but not All Mail – strange) views.

Alongside that, the Gmail team also added expanded subject lines in Basic HTML mode: now the subject (bold when unread) is followed by a (plain type) snippet of the first X characters of msg body (50>X<200). This feature has been present in standard Gmail like.... for ever?.

So here you have it: porting a November 2006 AJAX feature down to Basic HTML mode took Google mere 18 months. Progress.

("Mute" also discussed later:
http://blogoscoped.com/search/?q=Mute)

> That concerned the full-AJAX-y 2.0 view.

It was there in the old interface as a shortcut key, which is what Haochi was talking about, but has since been introduced as a menu item in the "Newer Version" of Gmail.

> porting a November 2006 AJAX feature down to Basic HTML
> mode took Google mere 18 months.

Given what I said above, since keyboard shortcuts aren't possible in the HTML-only view, it's only really taken 8 months to implement.

Maybe the new Gmail should have a lite version that lets you remove in a modular fashion all the features you don't need (e.g.: chat, mail prefetching, contact cards, rich text editor, label colors, virus scanning etc.)

Good idea. That would make a nice Gmail Labs project for one of the team.

I like the modules idea. A posteriori all this could be integrated with iGoogle (or something in a similar way).
I know you can have your inbox on iGoogle, but I mean something like Yahoo mail's.