Coming from Pro Tools I would love to see this feature, too!
BUT: Take into account that there might be some users who prefer the way it is now (one slider for both channels / Dual Pan-Plugin for individual Pan positions). So I would suggest that - if the changes comes - Presonus also introduce a Key command (e.g. "alt + drag") for handling both sliders combined.
I have brought a request that (sadly) handles the same topic: http://answers.presonus.com/24711/real-stereo-tracks
I must admit that - the Newbie I am - I should not have released this request, beause of this earlier thread here (which I hadn't realised). However it brought up, that there are users who prefer the existing method, so they should no lose their workflow by introducing individual L/R-Faders.