It is certainly good news for CWL but these are the flights announced some time ago and included in the Tui summer 2006 brochures.
I am currently looking at the Portland Summer 2006 brochure which shows these flights.
It seems that they will be flown in the main by the 738 to be based at CWL next summer (along with the usual 757 plus a part of the week 763 for the transaltantics), and the Tui group appears to be using them both as a low cost airline and as vehicles for their inclusive tour holidays. A pretty sensible move in my view.