I think it is good to change exercises occasionally [too vague?]. How about every 3-4 months. Heck, I've been doing bench, squat, deadlift, curls, lateral raises, blah blah for four years. In theory, I should have ceased seeing results LONG ago.
I disagree with the whole "muscle confusion" that seems to be fun to say. Your muscle has no idea what it is lifting. Muscle confusion is as simple as adding weight or changing the number of reps you do.
If you never add weight, or change the number of sets/reps, then no, your muscle will no longer be stimulated and change(grow).