I've written about my experiments to automate tag placing, a feature that would improve CafeTran Espresso immensely:
SDL must have been missing the same feature:
Trados has implemented this feature by allowing the user to activate it on a per-segment level by clicking on a button or by pressing the Ctrl+Alt+Insert keyboard shortcut (which can be customized). Segments that have then been provided with automatic tags are treated as "repaired fuzzy matches," which means that the translator will have to review them before they are confirmed and added to the TM. I like this rather cautious approach because early attempts by other tools that tried to completely automate this process were not particularly successful.