There's starting to be more interest in pulling Marta north to the Avalon in Alpharetta too. I think it will happen eventually, as the Avalon area and downtown Alpharetta are embracing more of the high density living/shopping/entertainment philosophy. A marta stop to take people to jobs and things in Atlanta is kind of a no brainer for attracting younger professionals that are attracted to those townhouses and condos. I think they're thinking going for Decatur North. You're not going car-free in Alpharetta anytime soon, but I think a Marta stop fits the philosophy, although its nothing more than talk yet.
Which is to say nothing for the massive amount of retail/restaurant that has opened and is planned, and isn't going to be filled by the folks living in half-million dollar homes nearby. They're going to need the train going there just to serve all the rich folks.
This will be of interest to you Atlanta folks. It's called The ATL and will consolidate MARTA and other transit operators into a regionally-functioning system:
• The ATL won’t go into effect until Jan. 1 (2019)
• The ATL governing body will live inside of SRTA/GRTA
• Chris Tomlinson, who is the Executive Director of SRTA/GRTA, has been chosen to serve the ATL’s interim director
• The region’s various transit agencies will operate under the unified name by 2023, including MARTA and GRTA
• Counties included: Cherokee, Clayton, Cobb, Coweta, DeKalb, Douglas, Fayette, Forsyth, Fulton, Gwinnett, Henry, Paulding and Rockdale
o Each county in The ATL’s footprint will have the option to hold 30-year T-SPLOST referendums to create special sales taxes of up to 1 percent to fund transit projects in their county that were identified in the regional transit plan
o “Importantly, the regional transit legislation provides flexibility and autonomy for member counties, who must “opt in” to any specific project or funding mechanism"
• House Bill 930 also provides a hundred million dollars to expand transit: "Georgia’s 2019 state budget will include $100 million to fund statewide transit projects". This appears to be over 10 years, and is only a $25m increase versus the prior budget year commitment to transit
• “House Bill 930 creates a seamless, unified transit governance and funding structure across metro Atlanta..." - Rep. Kevin Tanner, R-Dawsonville (The implications of this need to be investigated further)