Here are some of the key Detroit development stories to watch in 2013:

Rock Ventures' Z-shaped parking garage and retail

Rock Ventures, headed by Quicken Loans Founder Dan Gilbert, is

that will zig zag from the corner of Broadway and East Grand River to the corner of Gratiot and Library. About 33,000 square feet will be dedicated to street-level retail. Gilbert told MLive last month that retail is a priority for his development plans in Downtown Detroit going forward. He reiterated that while there is interest from major national retailers, he wants development to be calculated and "done right." The Z-shaped project is scheduled to be complete in December 2013.

Rock Ventures' latest downtown building purchases

In 2012, Rock Ventures acquired eight buildings totaling 630,000 square feet of commercial space,

. The latest purchases, including a residential building, bring Rock Ventures’ downtown Detroit real estate investments to 15 buildings totaling 2.6 million square feet of commercial space, and three parking structures for a combined 3,500 parking spaces. As mentioned, ground-floor retail will be a key component of these developments and it will be interesting to see what takes place next on that front. But retail space is only a fraction of the thousands of square feet these structures have, and Gilbert has been keen on attracting companies from the suburbs and beyond down to Detroit’s core. Which companies will be moving into these buildings?

Plans for a new Red Wings arena and entertainment district

Construction may not begin in 2013, but this year we should be able to at least get more specifics on

in downtown Detroit, announced by the Ilitch family’s Olympia Entertainment last month. Olympia disclosed the development while also saying the state needed to pass legislation that would free up Downtown Development Authority funds to help pay for it. That legislation cruised through Lansing last month and has been singed by Gov. Rick Snyder. An exact location for the development has not been released, nor have any layout designs or building plans.

The David Whitney Building in Downtown Detroit.

The David Whitney Building

The Broderick Tower and The Auburn were seen as two successful developments in Downtown and Midtown, respectively - two areas where demand for housing has not been able to keep pace with development. The David Whitney Building, across the street from the Broderick Tower at the edge of Downtown Detroit, will likely be the next major housing development to come on line. In December, developer David Di Rita told the New York Times that

, and is scheduled to be complete by early 2014.

The State Fairgrounds site

Former Michigan State University and Los Angeles Lakers basketball star Earvin "Magic" Johnson, former Detroit Deputy Fire Commissioner Marvin Beatty and Joel Ferguson

to the state Land Bank Fast Track Authority. The trio's plans, which are now subject to state and local boards' approval, call for 500,000 square feet of retail and housing at the site, located at Woodward Avenue and 8 Mile Road.