This article is from the Apple II Csa2 FAQ, by Jeff Hurlburt with numerous contributions by others.
If the best Apple can do for its II line turns out to be a "new IIgs" with 1MB of motherboard RAM and 128K of sound RAM plus NO upgrade offer to current IIgs owners... Well, the next "Apple Fest" could turn into the first "Apple Frost". As to movement on the 'II manufacturers upgrade front', I have yet to here a peep from Applied Engineering, Comlog, Western Design Center, or anyone else in the business. (Like, where are the Japanese when you really need them?!) So, to get things rolling, here's a specific proposal: Since the big problem with any worthwhile upgrade is maintaining current compatibilities while extracting graphics control and output from the motherboard kluge, why not put everything on a single, slot-pluggable board which also plugs into the motherboard 65816 socket? "Everything" includes an 8-10 MHz 65816, cache RAM, 640 x 400 (at least) x 256 colors graphics controller, an input (via a short jumper chord) from 'old graphics' output, video output & switching circuitry, ROM's, 1MB of RAM, duplicate sound system with 256K RAM, sound input for 'old sound' output (via another jumper chord), and a mini-connector to drive a 'to be developed' improved disk interface. The board amounts to a vastly improved IIgs which can, when asked, take over the motherboard and work lik e the old machine-- NOT, to be sure, so dramatic an approach as some might wish; but then, the idea is to 'keep it simple'.