After a little search on Curse and WoW Interface i found 7 usable Addons (tested with WoW 5.4).
If you are missing an addon in this list? write a pm and i test it.

Panels / Bars
Panels and bars with more or less fine granular configuration options.

• Bazooka
• ChocolateBar
• DockingStation
• NinjaPanel
• TitanPanel

Buttons
Thats are Addons to display databroker sources as single placeable buttons and docking functionality between the single buttons.

• Fortress
• StatBlockCore

Others

• LibDBIcon - A library to add any single broker of an addon as minimap button to the minimap. It's your choice to use it.