As I write this, crews are erecting two huge signs announcing, "Future site of the Parkhomes." These are townhouses that will fill in the awkward spaces around The Park At Lakeshore East. Specifically, between The Lancaster and 400 East Randolph.
In this picture, they'll go in that space between the parking garage wall and the road.
They'll probably also fill in the space between the park and 340 On The Park, in addition to the previously announced grocery store (a Treasure Island, if I remember correctly).