Correct, the standard cab SD70s are being rebuilt into SD70ACCs. These will basically be SD70MACs with SD70ACe style cabs. All of the standard cab Dash 9s are being rebuilt as AC44C6Ms. A good portion of the D9-44CWs will also be built as AC44C6Ms, but they are also testing out two AC44C6CFs. According to a post by NSDash9 on their facebook page, "The AC44C6M's are built to GE specs using GE components. The AC44C6CF is a CAF USA design that will use CAF USA and other aftermarket parts."
If anyone is a NS nut like I am, check this site out for NS locomotive info.
http://www.nsdash9.com/roster.html