You should be as it's not true. That same site reported earlier that the GTX350 would be 45nm and has been running a long series of BS rumors. If you looks around the other forums you will see that nobody is taking it seriously.
There may be something coming, as Ive heard as well, but it wont be ythis. The power envelope simply wont allow something like this. Youd need special power hookups for it. Also, one look at the clock speeds on something that huge and then your talking a huge heat problem. Default on the G280 is what 607 core speeds? Gimme a break. Look at this and compare to whats already been released.
738 with oc, yes, and then look at the power draw after the oc. What Im saying is, thats over a 30% core increase which would more than take away any die shrink, even adding in the reduced power using GDDR5, plus the compatability of the card even using GDDR5, which no ones heard a thing about. We all knew ATI was using it well before their cards arrived. I also find it hard to think we wouldnt have heard about that as well. If all the speeds are ramped up, and you throw in the die shrink, youre still talking about a G280x2 power demand, which I just cant see happening