http://www.letraset.com/tria.asp

Letraset have designed a brand new marker system. We are very proud to introduce a new Tria Marker with improved design and updated colour range. The new Tria Marker presents the unique familiarity of 3 nibs yet has a modern ergonomic design and boasts a number of key developments over it's predecessor.
Looking good

The new cartridges look easy enough to use but I'm glad that they will still be selling the ink bottles (gotta love ink washes, and hopefully they will be cheaper than the cartridges too)