There currently is no option to subscribe automatically, but this might be included (however we can't promise this) in the workflow feature which should be in our next major update (6.1). Currently you can select all the tickets you want to be subscribed to on the all tickets page and then select
Agents -> Subscribe self from the actions menu.
Our wishlist is kept internally since most of the time we're unsure whether or when development will start or even whether the feature in question will make an update (due to time required for testing etc.).