The update had moved XBLIG from its previous spot in the Games & Demos tab of the Games Marketplace into the Speciality Shops section, alongside the Avatar Marketplace, Rock Band Music Store and other things people don't look at when they want games.
The intent of the Specialty Shops section was to provide access to marketplaces that focus on a specific type of content, with unique ways of sorting through that content. We wanted to give Xbox Live Indie Games that full marketplace experience and felt this was the best place to do it, alongside other popular channels like the Avatar Marketplace.
In fact, since the launch of Avatars, Xbox Live members have made more than 290 million customizations to their Avatar's clothing, so we expect many people to regularly visit the Specialty Shops section.
The XBLIG store is now once again on the Games and Demos section.