It seems much demanded “wifi always on” feature is already a part of new WP8 builds. It has now been found to be present on Lumia 920T after earlier being reported to be seen on “HTC 8S“. Apart from this Lumia 920T has a Call Blocking list which allows users to intercept calls or SMS messages and apply rules to them including blocking them. The call blocking seems to be an added feature to WP8 software done by Nokia on its devices only.
Knowing Nokia, we may see thee features coming soon to other WP8 devices as software updates.