GPIB is going extinct. It is basically an obsolete protocol. Most forward thinking hardware designers are using in-system reprogrammable devices, and replacing buses, like VME, GPIB, etc, with Ethernet. Ethernet as a bus essentially allows hardware independence. I good communications specifications using UDP/Multicast will be the direction to look in. At the local hardware level, intercopnnects using high speed SPI serial, which can move large words quickly with only 4 lines. Saves on board layout and complexity. Make hardware designs as generic as possible, digitizing inputs and recover outputs from digital sources, and make designs modular, high on reuse.

- In system reprogrammable FPGA's
- Programmable I/O devices, as Fred brought up, from Parallax
- Embedded processors, PIC's by Microchip.
--- PICs uses networks
--- PICs have hardware support for serial and USB
- Network as your system backplane
--- UDP for fast data transfer
--- Multicast, a variant of UDP, do not require live connections, and can be used by multiple devices simultaneously

I have seen, but not used, controllers that are built into RJ45 connectors, with I/O and built in web server. I really need to check these out.