Tipping point-minus-transit potential, yes. I think there is a ways to go with critical mass yet. It's beefing up, but is still going to take a lot of convincing (particularly to retailers) that Central Detroit can support stiff market rate retail amenity. I'm not doubting that it can't, but I think true critical mass would set a standard and status quo that most middle class retailers and businesses can establish without high risk.
I think what we have now are islands of what we'll have in the future. These islands need to have contiguous connectivity, including better efficiency in crossing Woodward. When that starts to be accomplished, I think a firmer understanding of critical mass will start to take hold.
To illustrate my point, I kept saying to myself today as I was photographing the properties was..."well, someday soon all these developments won't HAVE to have gated parking." But for the time being (until we can reach critical mass), it's just a necessary evil. I even had to roll my eyes when I was riding bike up Cass near (south) of WSU and still find piles of fresh automobile window glass car-lengths apart, block upon block on the curb. Woodward and John R. have still have this problem too, as do the east-west streets.