I have an idea that might fix the odd pin spacing issue while maintaining compatibility with older shields.
Could a second socket, or even just pads be added just below the first (Aref through 8) header that were on 0.1" spacing? It looks like their would be room to do this.
I tried to modify the reference design with Eagle to show what I was talking about, but I'm not good enough with Eagle yet to make it work. The only Issue I can imagine would be eliminating the space between the first and second headers. If the space needed to stay, a few components would have to move slightly to accommodate the change. This would maintain the same board dimensions and footprint but allow an easy path for people wanting to build their own shields with protoboard.
For all the bitching about the pin spacing, I'm surprised that no one makes a shield that uses offset pin headers that fit the Arduino and translate to even pin spacing for bread-boarding.
Could a second socket, or even just pads be added just below the first (Aref through header that were on 0.1" spacing? It looks like their would be room to do this.
As stated by mowcius, Seeeduino (and others) already does this on their current board designs. There is also the 'bent' header connector solution ( Arduino Offset Header - 8 Pin - PRT-09374 - SparkFun Electronics ) that makes building shields with standard .1" spaced protoboards pretty simple.
The 'odd' spacing was an orginal design mistake, but it will always remain with us due to the large number of legacy shield boards already in use.