When we have a new hire the HR director takes them around to meet everyone. Its expected really to just be met-and-greet thing...very quick, just a few minutes (if that) with each person.
Sometimes the person only says hi and they look forward to working with me. Others ask what I do for the company. Some comment on the office decoration I have, asking questions about it to put the ball in my court, so to speak.
Its hard to say what is expected at a particular company though. You might be asked what your job responsible will be, where you came from (last job), how long you have been in the field, etc so be ready for that too.
BeeBee