Interesting, but I'm inclined to believe it's incorrect. ATi's press release stated a 128bit memory bus for both the FireGL8700 and 8800. Their Public relations department is also reporting the same 300/300 128MB/128bit for the FireGL8800 they were before, and 275/275 64MB/128bit for the FireGL8700.
Besides that, I doubt they would want to give the 8800 that much memory bandwidth.... their still positioning the FireGL3/4 as being higher performance professional level graphics cards then the 8800, and with that much bandwidth the GL8800 might come a little too close to the 8800 under some conditions.