You probably know this, but updates are posted on the main support page as well. They just did an update for Design Extender (1.0.7) that showed up almost immediately. - Under Recent Fixes. The email notices are not as quick in my experience, but a good question. I imagine they will be posting the highly anticipated (especially for Mac users) 1.0.3 update on this forum as soon as it is ready - happy day!
Doug