I've been playing around with it since it was released yesterday and found out something very useful.
Elements 6 was bundled with Bridge CS3 whilst Elements 8 comes with Bridge CS4. Previously with PSE6, CMD+R would not open ACR, unlike in the full version of Photoshop.
The good news is that now CMD+R opens ACR direct from Bridge without having to open Elements at all.
The even better news is that it is the full version of ACR, complete with localised adjustment brush, HSL/grayscale, lens correction tabs etc!
It's a slight faff, in that you have to edit your shots via Bridge, then save the edits, then reopen the Raws [launching Elements normal hamstrung version of ACR] to convert them in Elements to a Jpeg or Tiff. An alternative would be to batch process them I suppose but I haven't tried that yet.
Just thought I'd give a heads up to all those Mac users who've just got the latest version of Elements.
) 
