The end is coming... the end of the P+S as a stand alone device. I am sure there are plenty of people don't own a seperate camera, but just use the camera-phone as a 'I've got something' camera.
The quality of the images on phones are increasing- big time. However, the size of the censor, the ISO, and 'lens' are the sticking points in my mind. Just like multi-purpose print/scan/fax/copy systems, the do it alls will never out perform single tasked systems... however multi-use devices are VERY useful for those who use them now and then. Throw in video, HD video, and holy crow. In the hands of someone who knows what they are doing- and they become very serviceable devices.
I would seriously consider getting an iPhone G4 just for the camera aspect in my pocket... Just as the article describes, the Chase Jarvis 'The Best Camera..' project is VERY true. I don't carry a dedicated camera with me all the time. I really have the make an effort to have my camera with me at all now a days. I have a hard time just slapping on a single lens and rolling out- I want to do more... control the lighting now that I know how... have choices of lenses now that I know how and what they all do.... a carry around camera phone? Would make me think a heck of a lot more and at least it would be with me.
I can justify the cost of the device... I can justify the use with the camera, the GPS. The only downside- the cost of the data plan. Seriously... there has got to be a way to bring that price down.
I don't ever see a hotshoe being ingratiated to the phone- but I somehow do see a PocketWizard app. =)