Just got the TBNT after interviewing with Virgin, so I feel as though I can freely comment on what we were told.
I interviewed last week with 7 others. We were told there were around 30 in the pool currently, and classes wouldn't start until end of summer. We were told if we were successful that we could expect a class date at end of year, beginning of next.
It seems the key to getting a call now is a LOR. I've personally applied every opening for at least 3 years. 3700TT, 200TPIC, and an associates. Every person interviewing that day had a LOR.
Good luck to future candidates.