Former APB technical manager Luke Halliwell has been writing a fascinating series of blog posts explaining what he thinks, from his perspective, went wrong. Three parts--1, 2 and 3--are done so far, with a fourth to come. Jolly interesting.
Hey, if you want more to read, point your peepers at Spelunky developer Derek Yu talking about finishing a game. I'm honestly not attempting to link this with APB, they're simply two articles I've read this morning. Perhaps you might read them too.