I googled it in the Dutch press about two hours ago and the earlier reports were that Guus had denied that he was going to Chelsea when he was asked about it last night. He added that he's happy where he is now.
Googling it again just now:
He seems to be willling to help them out temporarily. Money, money, money???
The name Rijkaard is also mentioned quite a lot in the Dutch press but some argue that he's not ready for a big team like Chelsea yet.