We are in a very similar situation. We are also DINKS who made a decision in January to begin tracking our spending, after reading through bunches of MMM posts.
In January and so far in February, like you, we have been able to save my husband's entire income and live just off mine. We feel exhilarated by this big step forward, as I'm sure you do as well.
Now it's about "gaming the system" to get each area of our budget down to its lowest level to see if we can save even more than 50% of our budget. We had a little setback this month/next month because we are in the process of moving to a more MMM apartment/neighborhood, so that will set us back for a couple months until we recuperate and keep plowing forward.
But nevertheless, it's nice to know we have a friend out there in cyberspace who is journeying along the same path as us.
Keep up the good work FOBStash! Drakmon and I are walking with you over here in NYC.