You kidding? When I was over there, everyone I came across said, "Oh, yes, I speak a little English," and then proceeded to speak with better dictation and grammar than any English person I've met!
Heh, that's not as much of a joke as it may sound: many Germans between 15 - 40 years old, particularly as you get closer to the larger towns and cities, will speak English. Further away in farm country, you'll need to know the basics in order to at least be polite, and to purchase necessary goods (food, beer, additional camping gear, beer, etc). I wish I had spent more time backpacking and hiking locally, but living there I remained mostly local when I wasn't driving down to the Alps for weekend skiing and snowboarding. If so, I'd be able to offer some useful advice.
Other than that, all I can really do is say I spent half a decade in Baveria, which is south-east German state. In particular I lived near Bamberg, which is a rather large town, but not so urban as Frankfurt or the other cities. It has a very traditional feel to it, but you're likely to encounter distinctly German atmosphere in any town you visit. Do make sure to visit every brauhaus you come across though--each one brews and serves distinctive beer that encapsulates the very essence of the town or village it was brewed in--plus, every little experience matters!
Anywho, again, sorry there isn't any real information here. Just figured I'd share a story and experience, maybe someone will get something from it.