If you want to stay current on news about Chicago high-rise developments, the SkyscraperCity High-rise Development News forum is a must-visit. The forum is often the first place to break news about Chicago high-rises.
According to the Chicago Architecture Blog post, initial construction at 345 E Wacker Dr, in the form of soil sampling, could begin as early as this week. A fun quote:
There are a number of people who just recently shelled out big bucks to live in Aqua who are now trying to figure out if their views are going to be blocked by the new building. Though renters at The Tides are really the ones who will be most impacted by lost views, and massive construction noise.
You can see more renderings at the Brininstool | Kerwin | Lynch Web site.