This might be a good starting point:
http://www.specktra.net/forum/thread/126632/complete-list-of-nars-products-long-post#post_1446654
You have the list of all permanent shades on the Nars website. For LE shades, you should google each seasonal collection and see which blushes were LE then.
NARS has a good habit of making new LE items permanent items. The last four blushes to have been released are still in the permenant line. Those four are Sex Appeal, Douceur, Dolce Vita, and Super Orgasm. New Order is being released with the upcoming seasonal collection on the 15th and it will also be permanent. I can't think of a blush in the last 3-4 years that has been released but hasn't been made perm.
In addition to the blushes listed currently on the NARS website, I know of three discontinued shades: Plaisir (which I believe may have been re-released briefly a bit ago), Ninotchka, and a shade called Sex. I am not sure if there have been other discontinued shades, but I think a search on Makeup Alley might turn up info (that's how I know about these d/c'd shades actually). HTH.
ETA: I just looked at the list MarieMary posted and that looks a
really good starting place. I'd even forgotten about Passion and I didn't know about Nirvana. If you just add the four new shades and the soon to be fifth I think you'll have a complete list.
It looks like Outlaw has been d/c'd as well.