Here is the timeline for my deposit, which shows that at least one deposit was honored:
- May 14 @ 10:14 AM CST --> Dwolla notified me that money was sent
- May 14 @ 12:16 PM CST --> Dwolla notified me that DHS seized Mt Gox's account
- May 14 @ 08:53 PM CST --> Mt. Gox notified me that funds from dwolla were deposited
I can't speak about other transactions with certainty, but from the fact that my deposit went through and the lack of any major "I lost $3,700 during the DHS crackdown" news stories, my guess is that all transactions that happened around this time were either honored or rolled back.