Do you know if the default will be to have it on? If so, then I think this will be a bigger deal. If it's something that people (meaning journal users on their own journal) can opt into and there's some automatic way to mark that they are using it (like the IP logging notification, giving linkers, readers and commenters a potential opt out) then with proper awareness and workarounds (like this post; thanks!) hopefully it wouldn't change too much. I think giving people options and information on what exactly happens with GA will go a long way. Of course, there is wank potential in everything:)

I think the key is partly technological choice and transparency, partly adjusting social norms (those who are used to blogs will probably be less freaked out by this change, esp. when you consider those widgets that display on the front of blogs where visitors are coming from are much more public), and partly individual management (people knowing what they are comfortable knowing or having known about them and how to manage that).