Yes, I also saw this and the supposed 'environmentally friendly' proposal is to be put up nhear the north-east end of the park and uses the woodland as a 'playscape' with slides, swings, climbing frames, etc. included. It is also meant to teach the children visiting about the woodlands' wildlife (which not much of will be left afterwards!)
On leaving Tatton Park via the Rostherne exit today I noticed a banner in a residents garden asking everyone to oppose plans to turn part of the park into a theme park.
As soon as I got home I checked the "Save Tatton Park" website, and there are plans to turn a large area of mature woodland into a theme park.