I didn't bother reading through all the replies but I know this is a concern to many hardcore fishermen. My basic rules:

1. Be yourself. You probably were before so just keep doing that.
2. Be honest with her about what you want and what you need. Neither of you has to get all of what you want but you both have to get what you need. Maybe fishing a certain amount is one of your "needs". It is one of mine.
3. Get her involved but do it in a smart way. Don't take her fishing in crappy weather or when the fishing is likely to be tremendously slow. Make sure she realizes it is about MORE than the fishing. It is about getting outside, seeing some rivers, eagles, and maybe taking some nice photos.
4. Kind of related to #3 is buy her GOOD gear. Down, Gortex, gloves, hats, and those little hand warmers can go along way.
5. Learn to read the signs. Relationships are kind of like driving and you must adapt to road conditions.

Good luck... to all of us.

-AP