I just installed 2.5 and noticed the Settings button no longer exists in the Project Tab/Panel.
Also when Right Clicking on a imported model the “Import Settings” option no longer shows in the dialog popup, to allow for swapping UVs channels etc.
Neil.
Import settings is now shown in the inspector when you have an asset selected (make sure you have an inspector tab showing).
My fault, I just found the details now appear in the Inspector Panel under (Mesh 3DSImporter)
EDIT: Cheers Matt, I posted same time as you LOL.