looks good, but i have three suggestions:
-
Power
How about adding a JST Connector instead of that round one? I found it easier handling JST stuff than any other solution ever. With such a plug, like in the duemilanove, you would have always rely on certain hardware but with a JST you could use whatever is available (most of the time anyway) -
Spacing
Looks like your board is Shield compatible: How about adding a second row of holes or headers to make it prototype board compatible? this would ease experimenting a lot. -
USB
I always liked Miniusb more. This is just a personal opinion, but this might be more useful and prototyping friendly as the port you use is quite high... -
Jumpers
Why not using switches like the Seeeduinos do? -
Auto Reset
Is it disableble?
But besides these suggestions the board looks very good for beginners!