I've got the same type of deal here. I just worry about skills getting outdated since I'm only working on an in-house system and doing mostly maintenance. But perhaps that fear is overblown.
I could easily hop to a gig with more responsibility and more opportunity for increasing my skills - but also more stress.
I feel like you'll never be out of a job long with a good work history, good references, and knowing your way around overall web development. Might not be enough for Facebook but it seems like enough for us.
I could easily hop to a gig with more responsibility and more opportunity for increasing my skills - but also more stress.