I don't think the 8600 has a good future at all, even for Direct X 10.
First of all, like with all Direct X 10 games of now, games are going to start being coded with Shader Model 4.1, not compatable with todays cards.
Then theres the fact its simply not powerful enough. It has trouble running some Direct X 9 games from what I've heard, so with Direct X 10, it has no chance.
Think of it as the 5000 series made by Nvidia a bit ago now for budget Direct X 9 playing.