I vaguely remember a paddock in this area too. It was rather ramshackle and almost offshow. I once saw several Swamp deer stags in there- 'surplus to requirements' I imagine.
I believe, speaking to members of staff over recent years, that the long term plan is to replace the wolves with African hunting dog.
Sorry Adam, I would love to be proved wrong and, if I am, fantastic! The wolf wood is a lovely area of Whipsnade, especially when the bluebells are in full bloom! I really couldn't imagine anything other than wolves inhabiting that enclosure because, as we all know, there's plenty of space at the zoo for two (possibly three?) species of canine.
Out of interest, what was there before the wolves moved in? I know they were in what is now Tiger Falls.
Personally I would rather prefer they went into Dhole, as a species which gets rather less attention than the African Hunting Dog in captive collections yet is significantly more endangered, with an estimated wild population of 2500 as opposed to the estimate of 5500 African Hunting Dogs.
As IanRRobinson said, its a pity they aren't prepared to have two, or even three Canid species- there is plenty of room and they aren't expensive to create new housing for- lots of chainlink and a small house or burrow system.
The mindset seems to dictate they will only get a species to replace another they go out of.