I swapped my phone out and the next day I was playing around with 'find my phone' on the new one (I have Mobile Me). So my computer shows me where my phone is - at the Apple store. They had said they'd wipe it before sending it away, but they didn't say it would be days. So I did a remote wipe myself from home.
Before that, however, I did have the phone play a sound for 2 minutes and display a message - Wipe this Phone! - so I hope the guys in the backroom had fun.🙄