After 12 hours on the road, 20 minutes in Canada (well, Quebec), and a night in a really crappy hotel room, we are back home, with freshly minted I-94s.
In the immigration office, they were hesitant to hand us the I-94s because we still have valid H1-Bs. I had to insist that they give us them to support our Advanced Parole renewal. This is way too complicated (and expensive) and I just want my Green Cards...now.
So, a tip for all you travellers out there: Regardless of your status, and the insistence that you don't need I-94s, never let them take them away, and try to get the border agents to issue them for EVERY crossing. I know it's a pain in the ass, but it's more of a pain in the ass to have to go back and get them.