BillSeurer
Eternal Supreme Dictator
They've done it since Jade Empire (Bonus characters with the limited edition) and back then they were still independent as studio (It was months before they joined Pandemic in that investment co-op and two years before EA bought up the co-op) but did have a publishing contract with Microsoft. EA wasn't in the picture then.
I remember games pre-Jade Empire that had bonus material (if not characters) for buying some special edition or another. Just off hand there was Fallout Tactics (Developed by Micro Forté and published by 14 Degrees East) which had some exclusive areas you only got with a special edition. That was from 2001 and Jade Empire wasn't until 2005.