After fooling around with the demo, I can say one of the bright spots of NBA Elite 11 is its commentary and presentation. The total integration with ESPN's graphics, wipes and music helps sell the authenticity of the call.
This video says EA Sports Vancouver - also responsible for the ESPN integration of NCAA Basketball 10 - recorded more than 60 hours of dialogue with announcers Mike Breen, Mark Jackson and Jeff Van Gundy, the well-regarded real-life A-team for ESPN's NBA broadcasts. I'm not sure I buy the claim that it was entirely ad-libbed - there had to be some direction and scripting. But yes, it's a very natural call that sounds like one you'd expect for a live broadcast.