All plants bloom in some sort of manor. It is a sign of a healthy plant. A lot of times tropical plants taken into a home type setting just don't receive the correct environment to produce flowers. I don't think the dieffenbachia is considered a annual, but not sure. If a seed pod develops, pinch it off, and cut way back on any fertilizing that you may be doing, just to ensure it won't finish up its lifespan. I have never myself seen a dieffenbachia bloom. I would imagine it would look similar to a spath. I would love to see a pic of it, if you have one. Another interesting thing about this plant, if you have kiddies around. The sap in this plant contains a pretty potent nerve toxin, if you ingest it your symptoms can range from temporary loss of voice, to death if you eat enough of it.

* * * *