The black Wii console, which should match the rest of your A/V equipment perfectly, will debut in Japan first at the beginning of August and should move to the US later this year.
Unfortunately, Nintendo has not released any kind of information or specs on this new black Wii except pictures of the box. It does have a "eye grabbing" look to it though but if thats all they did was change the external color, I believe Nintendo will be disappointed with the reception it will get.