The BBC have a fairly impressive ‘news centre’ at their Television Centre in West London, which handles their national TV and radio news output. So I imagine that Sky News felt that they needed to move up a gear to stay ahead of the news-gathering pack with a purpose built news centre. – Although they do seem to be doing okay as it is, with all the awards they are picking up. But the competition are not standing still, so it shows that Sky News are not resting on their laurels.
the current plan calls for an integrated newsroom/studio. Essentially the Main pres desk will be right in the center of the newsroom. If memory serves there are at least 3 different presentation positions around the newsroom as well as the main desk.