I would say some negotiations are still ongoing, as there is still 4 weeks to go. But I'd say they have quite a few confirmed.
It sounds like Emma and Rylan are possibly filming the advert for Celebrity Big Brother. I think Channel 5 are doing it right with this series, giving a month gap between the civilian series and the summer celebrity.
They must have a whole new theme lined up and are changing the house around. Very exciting. I remember in the Channel 4 days, the theme of the civilian series normally carried into the following Celebrity series.