But the thing is (and like you mentioned)...they have been given major reason to change. Cost being a major part of that. And I believe that is reflected in the NA launch sales. Sure, the One sold well, but the PS4 did better - and this, in a territory where the 360 has always been considerably favoured over the PS3. It is a big deal.
I think the combined graphics and cost advantage will have some effect. Not the be-all-and-end-all, but certainly a factor. Think about it - a lot of people buy these consoles primarily for COD/FIFA or other really popular titles like Assassin's Creed. If they know they can get a console 80 pounds cheaper that runs it better, at a higher resolution on their large flat screen TVs, then it will certainly have a positive effect on PS4 sales. Admittedly there will be a lot of people who don't know/care, but I wouldn't write this off.
People will indeed buy what their friends have, but said early adopter friends may have already made the switch to PS4. I think this gen will be interesting.