Not if it was added to the lost/stolen phone list. This blacklists the MEID/IMEI, which you're not getting around without hardware hacking.

Is hardware hacking really required? My S3 ran the risk of losing its IMEI when I was messing around with custom ROMs, but before a solution was found, people put up guides on how to change the IMEI with software and it looked easy.

Some time ago, I cloned the ESN of my SPH-A680 onto an identical model (using QPST). When they were both on and next to one another, calling me made them both ring, and simultaneously answering both let me hear audio out of both.

I doubt basebands have really changed - it's a culture of security through obscurity, with people unaware of the details assuming they actually provide their purported security guarantees.

I was under the impression that the IMEI was burned into the baseband ROM at the lowest level, seems I was mistaken :)

Whose lost/stolen list? A different SIM could be a different carrier. Eg, I switched from AT&T to Consumer Cellular with a SIM change.

Or you just ship the phone to another country. The lost/stolen lists are not shared internationally.