Have you got any monitoring software installed, such as FahMon? They can tell you how long you have left before a WU is finished. If you have been crunching 2 days solid it sounds like a large WU.
If you have only been crunching part of the day then it could be a long wait. However, even my 1.6GHz Celery in my laptop can kick out a WU within about a week [depending on WU] - only gets used maybe 4 or 5 hours a day.
SiriusB