Bee spring 2012 and the building up begins

Without wishing to encourage the evil eye, I'll say that this mild winter has been good for the bees. I weighed the hives in November and then again today. The east hive is holding steady. It has a single brood box with top feeder. The north hive has put some of the sugar water in storage. It weighed into day at 67.2 - that's brood box and one super. There's no excluder in between.
I opened the north hive today and it was "full o' bees." The incident I reported two weeks ago during a warm spell that looked like robbing was most likely the result of a brood burst with lots of new bees taking test flights. The yellow jackets were so aggressive during the fall I thought I had another robbing incident on my hands.The "war of the worlds" photos demonstrates how many types of bugs want to get in on the action.
Today, the temperatures climbed into the 70s. We're still six weeks from our last "typical" freeze date. I wanted to be sure that all was stable in the hive as I begin to ready for the build up and the nectar flow in April.
I have not tested for varroa mites since the fall. That's the next step. I used the newest natural agent, Hopguard, last September in the north and east hives to knock the population down. It doesn't kill varroa in the brood, just the active mites.