TR has been a money pit for NCsoft. They've held it open for a lot longer than it probably deserved from a financial sense on the hopes of turning it around. A number of other titles have been sacrificed on the altar of TR's continuance.

When TR shuts down, it might have its engine used for something else, but NCsoft aren't going to sell the title to someone else or open source it - why create a competitor? They won't make it free when turning it into a tax write-off makes the books look a lot better.

And, probably most importantly, NCsoft will shut TR down to remove their embarrassing association with it. NCsoft has shown it doesn't want to be a MMO publisher dragging around a host of undead MMOs behind it - it wants successful titles. If one of their titles isn't working, they aren't afraid to cull it.