Fantastic news (from a betalogical point of view): about 83% of todays most innovative applications are released in beta*.
Michael Arrington hand picked 12 companies for the Connected Innovators program at Supernova 12, 10 of ’em are in beta (or pre-beta):
lifeio* (by invitation)
PostApp* (private beta)
Protomobl* (beta later this month)
(see the beta quotient for apps inspired by flickr and apps inspired by digg)