2K forums, an admin has stated that the developer is aware of reported framerate issues encountered by several players in NBA 2K10. He's also put out a call to readers to describe any encounters with the slowdown, with the hopes that problems can be identified and resolved. The thread has grown to 25 pages at the time of writing this post.
If you've run into the problem yourself, get over to the relevant thread and recount that traumatic experience with as much detail as you can. Heck of a way to celebrate a franchise's 10th anniversary, eh?