The 10th should work for me ... I just need to confirm what day Machelle is hitting the Denver Stock Show. :-)
I like the alternating idea, and the proposed sequence (though I'd rather Planetfall before DW, but can go either way).
As for mixing it up, the third month of each quarter could be a variety game. I'm well set for Star Trek Attack Wing (and can lend multiple fleets), X-Wing, Babylon 5 Call To Arms (again multiple fleets, minis or chits), War Rocket, and don't forget we'll have STAR WARS ARMADA on our hands before we're ready for it.
For the Springs crowd, I'll be working up to a short Firestorm campaign, followed late year by an Integrated Armada-Planetfall campaign.