I think Nordic Hardware has somewhat of a reputation for scouring various tech forums and reporting what they read as news, so it's hard to say how much accuracy there is in those reports. But, seeing what AMD did with the 4890, it isn't too far of a stretch to imagine they'll tweak the design of the 5870 and release an updated version in the not too distant future.
The question is Fermi. My guess is that we'll see a paper launch / product announcement type launch sometime before the end of the year. By the time it arrives in volume, it is possible that the 5850x2 and 5870x2 will all ready be out, or very close. If we get a December paper launch and it takes another 6-8 weeks for Fermi to become available in volume, if these reports are to believed the 5890 (just guessing the name) could be right around the corner, not to mention the 5850/5870x2 parts it'll have to compete with. If that ends up being the case, I see some rough times for Nvidia over the upcoming months, unless Fermi is really a monster, but it's specs don't indicate that it'll have that kind of performance advantage.
All the above is just based off of various rumors that seem to be floating around, so all f that could be not close to the reality of what happens over the next few months just the same. Maybe Nvidia launches in November with widespread availabilit in December and teh 5890 never materializes.
There are a lot of different ways this could all play out.
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