talking to mike a while back, he mentioned that newer PC cpus will have a dual instruction channels, quad etc.. later on.
Windows will harness this and it will be apart of the DirectX core functionality I would imagine.
A simple approach might be to channel music and sounds down one and the rest of the game down another.
ai and gfx instructions would be excellent to divide up.
Its kind of happening already now tho as your graphics card is partly a cpu in disguise.
A lot of this would be underlying in DirectX and perhaps you could get access to it with a good knowledge to the dx sdk that can manage it.
In the meantime theres no real major use of it as most pcs are not set up this way just yet.
To improve speed always reducing the amount of actions per main game loop always helps.
Using timers can alleviate many checks per round.
You could emulate a threading aspect by basing actions performed in your main loop with timers.
instead of checking for the player controls every loop you could reduce it by half with a timer, things of this nature if fine tuned is not noticable to the user and helps with speed and control flow of your main loop.
DB is a linear syntax with a basic foundation so it might be hard to emulate actual threading.
It does have access to types so its not so data daunting with larger strucutres.