According to this article in Crain's Detroit Business the following are in contention. Notably missing from my perspective is the Ambassador Bridge.

"The landmarks will be featured in the new attraction’s “Miniland,” a miniature Lego brick landscape inspired by metro Detroit’s buildings, attractions and other notable landmarks.
Chosen after a first round of voting during which 1,100 votes were cast, the top 10 metro Detroit landmarks are:

  • GM Renaissance Center
  • Spirit of Detroit
  • Belle Isle
  • Motown Museum
  • Fox Theater
  • Guardian Building
  • Comerica Park
  • Uniroyal Tire
  • Michigan Central Station
  • Heidelberg Project

Legoland is asking its fans to vote on their favorite of the 10 on its Facebook page Nov. 2-16.
The winning landmark will be announced Nov. 18 and unveiled at a special event prior to the center’s opening."