Just been looking down the entries for this year and it is seriously strong, even beyond the big names:

Neal - 3 x series champion
Shedden - series champion
Plato - 2 x series champion
Tordoff - 3rd in Renault Clios & Porsche Carrera Cup, BTCC race winner
Hynes - f3 champion
Turkington - series champion
Collard - independent champion
Giovanardi - 10 x touring car champion (3x Italy, 1x Spanish, 3x European, 2x British, 1x ETC)
Jordan - series champion
Depper - Mini champion
Austin - British F3 & BTCC race winner
Stockton - British GT race winner
Morgan - Ginetta G55 champion
Cole - British Formula Ford champion
Geddie - European Supercar champion
Belcher - Jet Ski & Clio Cup Master champion
Newsham - Clio champion & BTCC race winner
Menu - 2 x BTCC champion; WTCC runner-up
Smith - Clio Cup runner-up
Goff - Clio champion

So that is 12 previous race winners, of which 7 have been series champions, add to that a Formula 3 champion, and a whole field of drivers who have had multiple successes in lower formulae. 20 drivers already announced who have won at least at national level - very impressive.