The Arcade project is a nice step toward bringing more residential and commercial activity to the heart of downtown [Framingham]. But "mixed use" alone won't breathe life into a moribund business district. If the Arcade complex is surrounded by uninviting concrete and asphalt, it's not going to do much for the neighborhood.
On the other hand, if the center has an appealing, well landscaped sidewalk area, perhaps even a small, human-scale (i.e. not like Boston City Hall!) plaza outdoor restaurant or cafe dining in nice weather ... that could truly bring vitality to the surrounding community.
There's lots more, of course :-)