It looks like I'm in the same boat as some of the others:
I did not receive an Order ID or an e-mail from BitInstant, but I did receive an e-mail notification entitled "Successful ZipZap Payment" from ZipZap.
Here is the info that I was given by ZipZap:

Quote ID  8702b891-b838-49d8-8ece-2856df79b00d
Event ID  ef336af9-e79b-4cdd-bf04-215a4199d2b7
Quote valid until  Thu Mar 21 21:35:11 2013
Fees (Not inclusive of ZipZap)  3.99%%
Amount you need to pay  $481.05 USD
Amount you will receive  $461.856105 USD
Expected delivery time(HH:MM:SS)  0:04:00
Guaranteed delivery time(HH:MM:SS)  1:00:00
Destination exchange  MtGox

As I've stated, I have not received any e-mail from BitInstant and would be very grateful if a support member could help push this through for me.

I'm sure that this backlog will be cleared up and taken care of within a matter of days at the very most.  I have had similar issues with BitInstant in the past and they have always made it right.  Hopefully my order will be addressed in the near future. Please help me, support! (: