Got mine together this afternoon:
I like it! I happen to have the components already, so it didn't take long after I received my board to get going. The silkscreening is clear and accurate, although I did have to remind myself of the LED orientation - I'm used to seeing a flat on the outline instead of a +. I think that's the only time I consulted the schematic.
Any shields that follow the NG/Decimilla outline will work just fine, as the ZIF socket is far enough to the side to leave plenty of room.
The only thing I can find to complain about is the board is trimmed a wee bit too close, but it certainly won't cause me any problems.
If I were to change anything, I think I'd rotate the ICSP header 180 degrees, as my AVRISPmkII cable wants to run over the top of the socket, instead of to the left where there's plenty of room. I also have the feeling that a disconnect jumper for the auto-reset (like someone did with a recent Freeduino board) would be a good idea. I haven't had any problems, but from posts on the forum I think it would be a good option to have.
I chose to use machine pin headers for the crystal to allow me to change frequencies or remove it as I prototype for different projects. I also found that the 0.1" pitch capacitor pads were just about right to solder some 1206 SMT caps on, since I didn't have any through-hole caps the correct size. This gave me the idea of creating my own Eagle components for caps and resistors so I can use either TH or SMT if I want, but that's another project.
As soon as I was finished soldering, I dropped a fresh ATmega168 in the socket, plugged in the ZIFduino's USB cable and connected my AVRISPmkII up to my Powerbook. I selected the Decimilla board (the ZIFduino is equivalent), selected "burn bootloader", then uploaded my test program and I was in business!
Kudos to Bitty for a very useful board, and to the Arduino team for a great platform to work with.