I also had problems with $10000 of withdrawals on Friday. I had to email Magical Tux a couple times about it to get his attention -- he's really overworked right now and trying to hire someone new. I finally got this response from him:
Hi,
It seems that Dwolla broke the sendMoney() api a few days before announcing publicly Dwolla Grid. We'll get this fixed within 24 hours and resend all the pending transfers.
Mark
I'm satisfied with this. Let's give him some time, I'm sure things will get fixed soon.