Merlin have a long list of parks under their control, including the likes of Alton Towers, Legoland, Thorpe Park, Heide Park and Gardaland. Given Macks mid priced range of attractions Merlin could add a lot of new rides to many parks for not huge amounts of money. I suspect for the price of a single Intamin or B&M coaster you could buy maybe 2 or 3 Mack coasters. Can the public necessarily tell the difference? A new attraction is a new attraction.
There are many rumours that in 2008 the Merry England part of Alton Towers will receive a make over and become a pirate themed land. The Splash Karts are expected to go to be replaced by a new ride of some sort. Well Mack have experience with pirate themed interactive boat rides, they recently installed one at Legoland Deutschland (another Merlin parks).

Mack could even provide a Pirate themed Supersplash as another new attraction for the area.

Hopefully over the next couple of months things will become clear and we'll find out if this was a social visit or a shopping trip.