I think that it is in fact ready for the prime time. However, I think that AMD will barely give a peep about K10 until it's virtually already been rolled out. Why? Intel has working 45 nm silicon and everybody knows it. Intel is also not afraid to push designs to their melting point if that is what it takes, and everybody knows that too. AMD is scared that if they tip their hand too early, Intel will realize exactly what it is that they have to beat. And they know Intel will put an even bigger foot up their butt of the engineers and get Penryn out sooner if that it what it takes to do so. If AMD can keep Intel unaware as long as possible, or lead them along into thinking that the K10 is a flop, it will maximize the time that it has an advantage over Intel and maximize profits.
AMD isn't big enough to battle Intel head-on and win, especially in a field where there is a significant R&D and capital cost. AMD has to be clever in how they do things in order to be able to pick up a little more share here and there without getting being forced into a war of attrition that they'd never win. They did get into one of those with the recent price war and look at what it did. Intel had to lay off workers, but they are now turning a profit. AMD is still bleeding. That is why AMD bought ATi- it's an area in which they can have a competitive advantage over Intel without having to fight them directly.