I am encouraged that the vision of future phases and the pushing of the City of Somerville is to expand this urbanist footprint to the rest of the development over time.
Absolutely. Keep in mind this is still just four buildings in an otherwise vast sea of vacancy. The success of these four buildings is
1) Their relationship with each other
2) Their proximity to the river, which serves as a natural barrier and perfect origin point for the development
3) Their not having screwed up denser-than-usual future development (read: Seaport Square's massive sidewalks and boulevards)
Case in point on the last: Take a look at how Parcel 9 neatly aligns with Grand Union Blvd on top and the pickup/dropoff road of Assembly Square Marketplace below. Each of the parking lots to the left of Parcel 9 could be redeveloped into parking garages and new buildings without requiring a funky roadway workaround. And they'd feel like a natural extension of this original plan.