I guess it really depends on whether you consider it as a problem or not? At their ages there are no health concerns about suffocation, etc. The only real concern is whether people are still having quality of sleep, etc and both partners are OK with the situation. It's really only "bad" if you think it takes away from your marriage and your relationship with her.
Many cultures are cosleeping at those ages. It's just not the norm for our culture.
Co-sleeping is a personal decision. There is quite a bit of literature out there that lists pros and cons to children in the adult bed. I personally do not co-sleep with my children. My kiddos have slept in their own beds from the beginning because that's how I was raised.
~ Christine ~ Mom to 2 busy boys and one spoiled lil' girl