And great work with expansion connectors, people can't really complain on the lack of modding possibilities. I just hope nobody will mention arduino shields now, there's simply no point
Sorry to dash your hopes, but I still think that to eliminate the chance to use a Ethernet interface is a big mistake. And the only most practical way of adding Ethernet is to use the $20 (delivered) shield.
Any computer interface has to be isolated, and the serial based USB is just ugly compared to USB.
Ethernet means you don't have to have a computer on the same bench, you get 1500V isolation, you do not need a program to talk to the power supply since you can use a browser, you get the SD socket, so you can have unlimited storage space for data logging, you never have to sort out some piece of software that has to work out what virtual serial port the USB is using, since it changes for each different USB port, if you have a wireless router on your network, you get wireless access from notebooks, ipads, phones, etc, you can have banks of power supplies that can all talk to one computer.
You get all of this merely by freeing up a few more pins.
In case anyone thinks accessing the power supply via a browser means some heavy duty stuff - that is wrong. A basic web server is one of the simplest programs you can write. You listen for a GET command string, and send back your data along with some stored HTML strings. To get started, that is all that is needed.
Now that Ethernet seems to have been ruled out, someone will have to design the isolated RS232 or USB ports, and they will either have to use a terminal program (missing in Windows 7), or actually write a custom interface program. All that extra work for the sake of 2 pins on the Arduino.
Richard