Opened up my hive to check and see if the first brood from my queen had started emerging and to open the entrance reducer up to the medium setting, and was surprised to see that the drone population had skyrocketed all of a sudden. From a fresh package with maybe 3-5% drones, I now had at least a frame and a half of pretty much exclusively drones - and my first thought was that I had a drone laying queen and my best laid plans were going downhill fast. But going back over my notes, I don't think these could possibly be from my own queen, she hadn't yet been released on April 10th (confirmed release on the 13th), and the check was on May 3rd - so 23 days at the absolute longest. Also, though I'm new to this, the capped brood really doesn't look like drone brood to me (I have some good pictures if somebody can tell me how to upload a picture bigger than 195kb).
So that leaves laying workers (and the eggs were all singles laid in the bottom of the cells), or massive drone drift. Is drone drift like this a common occurrence? Is there any way to discourage this? It seems like supporting a large mooching drone population could really make it difficult to build up for the spring nectar flows, not to mention being a disease vector.