The simple answer is 'yes', we do have to submit detailed plans for approval. This is more of a formality and exchange of views between the developer and the planners at WMDC about colour schemes and materials as well as the technical stuff like how many toilets / what access is available etc.....
As others have said though, there is no reason that the initial groundworks cannot commence straight away though, but don't expect it to happen on the 20th!
Then it's all down to 2 things - one is the speed in which the developer can get tennants signed up and two is the ability of Sir Rodney to tie up the funding promised and, possibly, additional funding to bridge any gap caused by the delay in 1 above!
I spoke with Sir Rodney recently and expressed my view that I thought it likely that we would be able to move in for the beginning of 2015 (the start of the next licence period), to which he commented that he was hoping to have it sooner!
I hope he's right and I'm wrong!