The FTDI chip is just a microcontroller running a closed source firmware, this one is 1000% more open source but nobody is bitching at FTDI for not releasing their code.
Absolutely right, and speaking as someone who has used the FTDI chip in the design of an Arduino-derivative, I think the new approach is brilliant. It really rubs me up the wrong way when I look at the bill of materials for the TwentyTen and see that the single most expensive part on the board is the FTDI chip - more expensive than even the MCU.
Quite apart from which it's a locked black box, while Massimo mentions that the source for the official Arduino solution will be released shortly. That means we go from a more expensive, closed source, inflexible device on the board to a cheaper, open source, and adaptable device.
From where I'm sitting, it looks to me like the Arduino team just made the FTDI chip obsolete. I think this will have ramifications far beyond just Arduino as other totally unrelated projects start making use of this approach as well.
The niggle in my mind is the issue of the vendor ID and allocation of device IDs. When you buy FTDI chips you don't have to care about a device ID, it's taken care of. With this ATmega/LUFA solution it's up to the developer to manage it, and unless the Arduino team are comfortable issuing device IDs under their vendor ID it will be a barrier to others wanting to build compatible boards. If you're building a small number of devices it's much easier to buy a few FTDI chips off the shelf and have them work immediately than it is to apply for a vendor ID (with the associated cost) and device IDs.
Obviously I have a vested interest here (TwentyTen (100% Arduino Compatible) | Freetronics, for example) so take my comments under advisement.
Jon
Practical Arduino: www.practicalarduino.com