The way forward is streamlining! Here is a blog article from the ECM team reducing the load time of the approx. 450KB core.js file, by loading it in the background.
http://blogs.msdn.com/ecm/archive/2007/02/21/building-a-new-page-layout-which-does-not-reference-core-js-but-downloads-it-while-the-page-is-being-viewed-thereby-optimizing-response-time.aspx
This also brings me to another point – if you look at the Microsoft.com site. This
is driven out of MOSS/WCM or at least the top umbrella pages are.
In terms of a public internet facing readonly MOSS/WCM publishing site – nearly all
the interactive functionality is not needed. E.g. lists, drop down floating menus
for items within lists (ECB Blocks), etc etc etc (site actions menu)…….
A large portion of the client side functionality to all these features is provided
by core.js. Of which MS here on there pages has done some extensive Master
Page modifications as……..there’s not a core.js to be seen………crop
circles…….floating
cars in Perth……what next…..?