The OAs are generally moved just prior to the start of the season. I am really not sure that there will be ‘many’ good OAs avalilable. We will need to wait and see if some of the potential Barrie & Brampton very good OAs move on.
I do not know what you consider an impact player to be, but I doubt the Petes will part with the assets required for the very best OAs. From what I can see, Guelph & NB have one probable OA each. I can definitely see NB moving a couple of their 6-7 RW & 6-7 LD to acquire OA and/or import LW/LC & RD. London seems to out source an OA often.