Hope all is well,
Now that the New GTX 580 is here , is there any major difference gained for video editing.
Not major, but minor.
I've read that it runs cooler
I have been running a GTX580 for the last week, it is not really any faster than the 450 (or 460's, 470's and 480's) with Premiere CS5.
It does run a few degrees cooler in my system.
While some people have said the fan noise is lower, in my system I didn't notice any dfference due to the number of cooling fans in the case.