The reviews are here and the verdict seems to be that this card is fast, heavy, expensive and loud.
According to the reviews I've read the GTX 460 has a great price, it is quiet, it uses less power, it performs as well of better than the HD 5830 and it can overclock very well. There are two models that have been developed. The $220 model has 1GB of 256 bit GDDR5 and the $200 model has 768MB of 192 bit GDDR5. Based on what I have seen, both models overclock very well. For an example check out this graph from [H]ard|OCP.
This is probably the largest overclocking roundup I have ever done. Lots of sites decided to put Nvidia's overclocking claims to the test. Then there is the additional data that comes as a result of there being two different models. The 1GB model is on top and the 768MB model is on the bottom. As you can see the 768MB version is just a little more overclockable than the 1GB model.
Are these the design drawings for the GTS 450? Will the final PCB look as cool (a black PCB with red printing) as these drawings? I'll let you be the judge.