Nothings been published yet apart from FPA. At Zandvoort we had the BMW 1 Championship + their version of the Silhouettes, standard chassis with Mondeo / Focus type bodies. I think they had 40+ cars, made for some fantastic racing.
I wouldn't expect more than 3 support series to race during the weekend, they tend to spread the timetable out to ensure any drivers giving us cause to work don't cause issues with the TV schedules. Its a bit like the F1 weekend but with reasonable gaps, and we get to visit the whole circuit rather than just Bernie's "safe zones"