Will a website like Patients Like Me ever be able to replace doctor to patient communication? I don't think so. Will it begin to integrate, however, I think it definitely could - and maybe it has already. As I've been exploring the site, I've noticed that it's suggested often times, and possible, to print out whatever you like to take to your doctor. You can take your doctor your progress charts (very handy), or even take a print-out of a new clinical trial that you've been matched with on PLM as a possible treatment to talk over with her, or maybe some of your PLM friends have tipped you off about a medication they are taking that seems to work for their disease.
In short, a website like this and all of the new media communication that takes place on it can transfer into communication in your "real" life, your medical future. This kind of thing can help your prognosis in a big way or maybe in a one in a million way - any way is a good way, regardless of who it ends up helping.