Strange time to make a decision like this and its really not fair to the club or the fans.
Obviously his head wasnt in it (or his heart, whatever) and so to leave is a better decision than to hang in there half heartedly. That said, along with Villa, there is another club with no manager so early into the season which hardly gives the best situation for success.
It brings me to think of David James, who went to Bristol City with hopes of challenging for promotion and he spoke of an ambitious side with an ambitious manager. I wonder what he must be thinking now, as i assume that talks with the maanger would be one of the key things when choosing a club to go to. He's basically a signed a contract with a manager who has walked out a week later.