ATI to roll out 512MB GPU… but why?

So basically, ATI seems to be slapping on twice as many memory devices onto their Radeon X800 XL graphics card (which sports 256MB, natch), adding $150 to the price tag, and planning to ship it out (both cards pictured; 512MB version on the bottom) — despite no observable performance increase as a result of the memory boost. That'll be a neat trick if they can pull it off. Even more curious is the fact that they won't even be putting their own name on the cards — it will only be manufactured by ATI's partners. So what's the deal, ATI? You hopin' to pull a fast one on some well-banked gamers who just need a place to plunk down their $449?