Like voxel says, availablity isn't really determined. Shipments are suppose to start at the end of the month and ramp up quickly. And merom core are probably only closer to 10% faster clock per clock than current core duo's, and model availability is unknown. Merom should hit it bigger with intels new platform, which I believe is launching in Dec. AndandTech just put out a good review if you want to know more.
I would be more concerned about your processor needs. You mention you need a "power cpu." SUre you don't need a PowerPC? Well it seems that everything media related is done on a mac these days. I'd look into a MacBook, if that's so. Dell, HP, Lenovo and Toshiba all make quality products if you're willing to spend the money.