Virgin do not employ inexperienced pilots, and currently have no corporate interest in sponsorships (despite some rumours to the contrary). For each job available, Virgin can guarantee several hundred experienced and qualified applicants.
British Airways discontinued their Cadet sponsorship scheme in 2001. Since then, they have adopted a policy of obtaining their (small) ab-initio intake directly from the graduating courses of the Integrated schools. No investment is required on their part, and they get plenty of people. It seems unlikely they'll need to alter this policy. The majority of their intake is pilots with between 500 and 3000 hours, mostly already qualified on BA types.
Sponsorship - in the sense that someone else pays for your training - is essentially dead.
Scroggs