If it's a fully enabled GF100 chip it makes more sense to call it a GTX 485 or 490 than a GTX 580. Either way, I'm personally not interested. Fermi isn't a bad chip (just warm), but with the 6-series launch imminent I just don't see why someone in the market for a high end card would want this.
Perhaps because the 6000-series cards so far are disappointing and slower than their 5000-series counterparts?
As for any additional 6000-series cards coming in the next few months ... well that is the next few months. Those rumoured cards are likely to be higher-end offerings with high power consumption and noise.
We have no idea what the GTX 580 could be. It could be a GF104 core on steroids. The power/performance ratio of the GTX 580 could be very good. We just don't know yet.
By the time those high-end 6000-series cards come out, it's likely this GTX 580 will be out, and also likely that 470 and 480 prices will drop.
How does a 580gtx fit in the lineup? Would it not make a lot more sense if we were talking about a leaked slide that showed a 485gtx or a 490gtx? Why is the inconsistency of the name of this, as of this point, fictional card being completely dismissed by those who support it's likely existance in the near future?
It doesn't make a lot of sense for a 580gtx to be released in the near future. There's not any conspiracy behind the reasonable thought that presents such an argument.
How do the 6850 and 6870 fit into AMD's lineup? Higher-branded cards numerically, yet slower than the 58xx cards.
The GTX 580 would guaranteed be faster than any 4xx series card, so at least the naming would make sense. Besides, we don't know what this 580 card will be. The rumoured GF110 could be a significantly reworked core, enough so that it warrants a 500 series designation. We just don't know, so let us wait and see shall we?
At least ATI doesn't take a GPU and proceed to rename the hell out of it. *Cough G92, cough*
No, all they did was take a GPU, tweak it a bit, add some new features, give it a HIGHER numerical product name, yet it performs WORSE than its 5000-series counterparts.
I'd say what AMD did is worse than what Nvidia did.
Not only are the 6850 and 6870 higher numerically than their 58xx-series counterparts, but they are SLOWER.
This is keeping in mind that these 6000 series cards were HEAVILY hyped by AMD fanboys and AMD PR personnel posting on forums.
I saw many tech, computer, and gaming sites and forums inundated with AMD 6000-series card hype. I saw people saying ridiculous things like the 6000-series cards would destroy the GTX 480 in performance.