I have a desire to see a "smart" ethernet interface, capable of replacing (for example) Wiznet modules, but having the ability to be user-programmed. A likely solution would have a microchip ethernet controller connected by SPI to a PIC24-class CPU, with another SPI interface to connect to the host system. TCP/IP implemented on the PIC24, and a sort of "sockets over SPI" software interface to the host. Ideally, this module would be SW compatible with an SPI-connected Wiznet module, but exact compatibility is less important than implementing a similar complexity of capability.
This is in fact very similar to several of your existing boards that include microchip ethernet and PIC24 chips, including several of the "stalled" projects. In fact, software-wise it could probably be prototyped on one of those boards...
However, like you I am less than enthusiastic about the restrictions imposed by the Microchip TCP stack. What is the status of alternate TCP/IP implementations for PIC24? I see there was some traffic last year about uIP on the web server board; was that actually "finished" ?