I haven't checked it myself, but I've seen others report that on the PTS the items with changed bindings are "new" items, and existing items aren't changed with respect to their current binding on live.
I haven't checked it myself, but I've seen others report that on the PTS the items with changed bindings are "new" items, and existing items aren't changed with respect to their current binding on live.
The oddest thing I noticed is that some sets that were renamed are automatically renamed, and some aren't.
The bonuses were automatically changed (if they changed) for the non-renamed items, though.