It very much depends on the type of approach, aircraft, airfield, weather conditions etc. Using the autopilot helps with what is already a high workload in these circumstances and is usually mandatory on most aircaft in low visibility approaches.
For example the aircraft I fly can do a CATII landing with has a the typical minima of 100' with a runway visual range of 300m (varies for each airfield). If we become visual by decide, then the autopilot is taken out at 80' and a manual landing carried out.
Here's a CATII approach I made into BHX a few days ago
http://www.youtube.com/watch?v=9B5v8UOKAso
For a CATIII approach the autopilot needs to be capable of autoland.
ATC have stricter procedures in force in low visibility and we will not be cleared to land until they are sure that the runway is clear. Most major airfields have surface movement radar which allows them so see where the aircraft are on the ground. If not they have to wait until the previous aircraft calls runway vacated or airborne.
Hope that helps.
Merry Christmas