After a proper winter drought, this plant finally decided to flower (I've had it since Feb 2011 - it's grown quite a bit since then). It seems that it's cruel to be kind to many Dendrobiums, which really require a full on winter drought before they'll even think about flowering. Under this new treatment regime, several of my more recalcitrant dendrobiums decided it was time to flower.
I've recently moved this plant from its location right into a window, where I think it will enjoy the additional light. It's getting close to the time I ought to start reducing watering those winter rest plants too.