Kalypso Media now offers a new Megalopolis DLC pack for Tropico 4, adding a new campaign, new avatar clothing, and more to the island dictator sequel. This is not mentioned on the World of Tropico, but they say the DLC is now available for the Windows edition though the Kalypso Launcher and various digital distributors, and is expected for the Xbox 360 edition later this year. Here's word on the pack:

Build the largest city in the Caribbean! It’s up to you to decide how to deal with the problems that come with a massive influx of immigrants looking to join your society. Manage issues like unemployment, over-population and food shortages. Make use of the Conventillo, a cheap new residential building that maximizes living space at a minimal cost. As El Presidente, try on a decidedly more old-fashioned suit and spice it up with a classic monocle and mayoral necklace. The new bureaucrat trait helps you build cheaper residential buildings and earn bigger profits with the “building permit” edict.

• New building: Conventillo : Cheap housing with plenty of room to spare, but degrades over time and has to be frequently repaired
• New trait: Bureaucrat: Build cheaper residential buildings while earning more profits from the new “building permit” edict
• New outfit: Mayor (male avatar), includes monocle, dress suit and special necklace
• New mission: Megalopolis