This is planned more or less for 3.2. Class import/export functionality with template. This means that you can e.g. import a ready made forum to your site.
For now I use svn update for having a directory filled with the latest stuff from the trunk. Most directories are then symlinked (except var , settings/override and siteaccesses) to a live site to try out the progress. Still have to do manual database upgrades by inspecting the upgrade sql files.
