I think they should come back nex year. before their sister died, I thought Venus should not come back. If her injury is healed, I thought she should take time to work on her weaknesses, particularly the second serve and the forehand. She really did a lot on those two shots in 200/01 and they have digressed. Strengthen those shots, and get her hunger back. I just thought the whole of last year, Venus did not want to be on tour! She looked tired of the whole thing, and she actually said so at the end of the US Open.
On the other hand, if she makes those improvements, and she is driven at the beginning of the year, I feel sorry for the players ranked above her, who will actually draw her earlier because of her low ranking!