A tad too Alewife-y for my tastes, but certainly a good infill development. Looks like it will do a lot to mitigate the jarring visual impact of the apartments on the corner at Mass Ave and Beech St which will be very welcome.
I second the note about the parking, and would add that building a single-family home and garage on the back side of this lot is also a shortsighted waste of buildable space this close to the T.
As for the car wash, as of May neighbors were waiting to hear a pre-trail decision from a suit against the City of Cambridge, though I'm not sure if any conclusion has been reached yet. It's an inevitability, of course, but those neighbors opposed to the project have been especially determined to exhaust every legal option available to them.
Between this project, the Miso Market development, the Porter and Beacon Hotels, the development at the old Gourmet Express, and a few other recent projects (including on White St and the Lunder Center), Porter Square has really seen a flurry of activity in the past couple of years. I have also heard that a new building is also being proposed for 1718 Mass Ave (the single-story retail block including Cambridge Trust and Boca Grande), but haven't yet seen any renderings.
Personally, I hope the trend of expanding single-story retail expands to Davis Square.