What has kept it on the ground?
AFAIK mostly engine troubles. The
EuroProp TP400 is a very ambitious design, the second-largest turboprop there is, highly efficient and not slow at all. But it had its share of teething problems.
Didn’t they first roll this plane out last year?
You have to remember that the Boeing 787 rollout took place in summer 2007 and that aircraft still hasn't flown yet. I'm not dissing Boeing at all, it rather seems to be a sign of an industry-wide trend that new aircraft programs have gotten so complex these days, with such elaborate supply-chains that delays are almost inevitable.