From the picture in this very newsletter, the Jack port seems to be on the left of the phone when held in landscape mode (or am I seeing something else?). However, it seems to be very close to where the keyboard and the screen overlap, probably somewhere near the Esc key, or even higher. If confirmed, then it is not where the hands should be when holding the phone and typing; I don't think this would be inconvenient for typing.

[Edit] Or maybe this green PCB with what I think is the port beneath it actually goes on the very bottom of the keyboard case when held in landscape mode. If this is the case, then the jack would be on the bottom left corner. Perhaps a bit more in the way for a straight jack, but not too annoying for an angled one.

[Edit 2] Just trying to hold my phone in landscape mode as if I was typing on a keyboard (*sigh*, the last time I used my N900 or TOHKBD was long ago), the bottom left of the keyboard case would actually be much better than the top left.