If you're already in shape to do five miles a day, then you're ready for a real bike. Unless you have a self-contained tour planned for this year, I wouldn't get a touring bike to start with. Visit your local bike shop and ask them for recommendations for an entry-level road bike. Don't let them sell you a bike with a low-spoke count, high saddle and low handlebars that looks ready for the Tour de France. On the other hand, also don't let them sell you something that looks like a beach bike or has a cushy seat with springs or is only useful for riding down to the park or is a mountain bike. Tell them you want something on which you can work up to 50-mile rides (if that is indeed your goal). A price between $500 and $1500 is probably about right for this bike. This bike will also be good for van-supported tours (where a van is carrying your gear).
If you do want to go on a self-contained (i.e., carrying your own gear) tour in 2011, then my first choice would be to see if there are any shops with touring bikes in your area. If you have an REI near, visit them to look at the Novara touring bikes. Otherwise, you may be forced to have a shop order one for you. Consult the ACA buyers guide and ask your shop which of these bikes they can order for you.