Plans were recently unveiled for Riverfront Park, which will be adjacent to Martin Luther King Jr. Bridge and Main Street Plaza. You can read the full report here: Riverfront Concept Plan (PDF)
While there is a lot of work left to do, feel free to check out the plans and the reports concerning the property. There is no timeline for this project yet. As more information is made available, it will be posted on this page.
A cool feature that is also being studied is the possibility of creating a whitewater feature in the section of river that can be accessed by the park. Several options are possible, everything from a small white water play area to retrofitting the canal that runs behind the White Mill with adjustable white water features. That report can be read here: Whitewater Report (PDF)
It is important to remember that plans are just plans right now; nothing has been decided. The development of this park is a process and will take some time.