Arduino: What Direction?

In spite of the year-end hype surrounding the Arduino Uno, and while I like seeing Arduino hit its 1.0 release, other Arduino-compatible boards get me more excited. If Arduino is a low hurdle access architecture for the ATmega**8 line of microcontrollers, I'd prefer the extra circuitry to be optional:

• Power regulation: why embed regulation in each board when it's not always needed? And what about regulation or step-up converters for battery-powered projects?
• Board voltage: There are good reasons to use 3.3V or 5V depending on applications, why are so few boards switchable?
• Programming interface: While USB (and its decoder chips) is ubiquitous, so (still) are serial and ethernet, and (increasingly) XBee. Why not make the programming/serial interface optional or external?
• Real estate: There is only so much room in the standard Arduino form factor. Why not use that space for useful circuitry that would be tricky to locate externally?

$30 is a fair price for a board with USB, power regulation, and automatic power switching, but half of that cost is not for the Arduino-capability! This is neatly demonstrated by the $13 Diavolino by Evil Mad Scientist Labs, which has no power regulation (but pads if you want to install it) and a header for the now standard 6-pin FTDI USB-serial breakout interface. Arduino-compatible boards' regulation, voltage, programming interfaces, and extra features are listed on my comprehensive spreadsheet.

Here are a few boards comparably-priced to the Uno that may be more useful for real applications since they have the Arduino core but different circuits for power, communication, or extra capabilities:

• Wiseduino ($34 kit) has a DS1307 real time clock with backup battery, a 256Kbit EEPROM chip, header pins for the Adafruit XBee adapter, and 6-pin FTDI cable interface.
• Freakduino Chibi ($33 kit) has built-in 802.15.4 (XBee) radio and optional ($3!) battery voltage regulation so you can input from .7V to 6V.
• Arduino FIO ($25) has a MAX1555 LiPo charger, power regulation, and an XBee socket.

What do you want in an Arduino-compatible board? Please leave a comment!