I am delighted that Tenerife will be the new route because Tenerife is just the 10th busiest international route out of Northern Ireland so if that can be made to work then the other 8 can! (8? the 9th is to New York).
The only question really is whether the airport can sustain a "big bang" approach of announcing 6 new routes simultaneously or whether it is better to have a drip feed of a new route per year over the next 6 years.
Tenerife carried 57,000 pax in 2009. Previously it had been carrying closer to 90,000 so there was presumably a carrier loss or frequency reduction or something but it does mean there should be good demand for the Derry route. Curiously Lanzarote seems to have jumped ahead in the same time period.