You may have noticed that the countdown timer on mastercoin.org has been changed. Not the deadline, but what is going to happen when the counter reaches zero.
August 1st is Mastercoin’s first birthday. And just as when something begins to grow up and it begins to get its legs, so does this metaphor. We have an opportunity to provide a better platform, upon which we can build better features. The developers have convinced me that if the focus were on a single implementation, the half of the time that is spent working out consensus would be regained. We realized how quickly developers could adapt and create new features upon this new platform. We realized we could build a better MetaDEx on this new platform.
So we’ve decided to do that: instead of the MetaDEx being released on the legacy platform, on that day, we will present Master Core’s first official beta release, with testnet support. Happy Birthday, Masterminds!
tl;dr: coding it twice is silly, and doing it right takes a little bit more time. Master Core is the right way to get it done. (Master Core beta, followed by the MetaDEx is going to impress you.)
Current Master Core beta deliverable: August 1st.
Current MetaDEx deliverable: soon thereafter.
Omni 
I’m honestly super excited towards this launch … it’s going to consolidate our efforts and drive the development of the Master Protocol for a long time into the future.
I’d like to again thank Michael for insisting and selling us on the idea of Master Core – that work is very appreciated! (as well as Zathras and faiz of course!)