Frome the VA website.......

"Virgin Atlantic will be changing it's check-in baggage policy to a 'Piece System' across the entire network for all tickets booked from 25 November 2009. This replaces the change originally intended for launch on the 23rd September and now includes a revised allowance for passengers travelling Economy.

The changes are being made to allow us to simplify our policy, save costs, and lower our charges for passengers wishing to take additional bags. In the majority of cases, passengers who wish to fly with excess baggage in addition to their free allowances will pay less than they do now."

New Allowances from 25 November 2009

Number of Bags - 23kg Each:
Route:USA
Upper Class:3 Premium Economy:2 Economy:1 Infants:1