Compex Event Processing, which is Latin for "we think we've got some fast stuff here," will purportedly help Bioware with server and virtual world maintenance. According to the press release, BioWare will be able to "monitor the game environment in real time and immediately offer fixes for any game oddities, and to identify and react to malicious player behavior in real time to ensure game integrity" (emphasis added)." We hope this means BioWare is setting a high standard for themselves regarding bug fixing, network latency and quickly banning cheaters.
No indication on the graphical capabilities of the StreamBase engine or if BioWare will continue using the Hero Engine in conjunction with Stream Base. Though BioWare has a history of creating and licensing out their own game engines, it has recently begun using other engines -- the upcoming Mass Effect was made with Unreal Engine. No other details are currently known regarding their MMO project.