I like the way that Kathy had a shock return scene, and now she isn't on screen. We know she is alive, and she wants to come home but she isn't allowed. The references every now and again ease her back and make her presence slightly more realistic (relatively speaking) than her just walking back into the square and having everyone accept that she never actually died.
But what I don't like is how Phil Mitchell is, of course, involved. It weakens the premise that Kathy wants to come back, but can't. Of course, we are yet to learn the details, but I would buy into it more if she was seen begging with the police or a detective in South Africa - not in a London car park with Phil.
This return will only work if they humanize it and make it totally about people and not sensationalised rubbish. If my mum, who I had believed to be dead, returned after 10 years my life would be turned upside down. I hope we really see how big an effect this will have on Ian and Ben.