roslocate was moved to be a standalone/bootstrap tool released with rosinstall. This document outlines some of the distinctions and future directions.
roslocate requires downloading a very large index (several MBs) from the ROS.org servers. This is slow for clients and also has not scaled well with ROS' exponential growth.
roslocate does not know about distributions.
roslocate assumes SVN repositories.
roslocate does not support rosinstall
The latter two are related -- by supporting rosinstall in a first-class way, roslocate can also easily support multiple repositories.
Differences with new version
list and list-stacks have been removed due to the number of packages/stacks. Unless there is a compelling use case, it does not seem necessary to support in future versions.
The hope is to add 'search' back in once we upgrade the web site. The original roslocate downloads the index and does the search locally. We wish instead to query the web server to do the search now that there are ~2000 packages.
The svn command is supported for backwards compatibility use. The hope is to remove it in the future.
When the backend indexers are upgrade to support distro-specific information, a --distro flag will be added to return install information on a distro-specific basis.
rosinstall configuration tool
The hope is to use roslocate as an underlying library for a rosinstall configuration tool. The goal of this configuration tool is to build a graphical tool that can search ROS libraries and generate rosinstall configuration files.