Also worth checking out the Digispark (http://digistump.com) - the first attiny85 dev board to do the USB+Bootloader thing with a whole ecosystem of shields, code, and users (first commercially produced, many projects did it first) - glad to have Adafruit join us with their awesome take on the concept!
I would tend to comment on the class of boards rather than this specific one. Something like this is not what you are going to put into a consumer device that has a production run of a million units, but it is a great building block for prototyping or low-rate manufacturing. I am very interested in this, given that I am more comfortable with a compiler than a soldering iron. I could use boards like this to drop into any number of projects.
This is a great board for Hobbyists, students and in general for MCU development Newbies.
For more experienced embedded developers this is not in my opinion ideal. Especially when you can buy STM32F0Discovery board with 64KFlash, 8K Ram, 48MHz 32-bit cortex-M0 STM32F0 core with tonnes of superior peripherals and a debugger for around $8-$10. A free IDE (Coocox.org) supports this chip.
Other boards that are similarly priced also include the TIVA C Launchpad board based on a 80MHz Cortex-M4F with 256K Flash and 32K ram. The board also includes a debugger and works with TI's CCS IDE. That board goes for about $12-$14.
Caleb, Max forced me to say that red is better... Please don't ask me why :) And re the board, I could say that small is beautiful but after this nail color story, let me just thank you for another blog with cool stuff.