This week's Sunday Times carries an interview with the CEO of Virgin Group Josh Bayliss who says Virgin is looking to return to the UK railways as an Open Access operator:
www.thetimes.co.uk
Services to Europe are also said to be under consideration:
If these plans do come to fruition (and there is a long list of things in the past that Virgin has said were under consideration that came to nothing) it's unlikely that Virgin would go it alone and risk much of its own capital.

Why Virgin is returning to trains, by Richard Branson’s right-hand man
The railways, space, loyalty schemes… Sir Richard Branson’s empire has come unstuck at times. But chief executive Josh Bayliss insists it will come back for more

The finer details are being worked through, but he is looking at launching an “open access” operator, similar to the likes of Lumo and Grand Central, on the east coast mainline, which take full commercial responsibility for running services rather than being tied to state-mandated timetables. No final decision has been made, he stresses.
“The opportunity which open access presents to continue to provide that experience on the rail network is something that is very interesting to us,” Bayliss says. “We would love to be able to serve those customers who so enjoyed Virgin on the UK rail network.”
Services to Europe are also said to be under consideration:
As EU countries are forced by Brussels legislation to break up state rail monopolies, opportunities abound on the Continent, too. This is why Virgin is looking at a potential rival to Eurostar to run train services through the Channel Tunnel. “It’s a huge undertaking to establish a new operator in the industry and in that market. We’re continuing to advance our preparation and delighted with progress so far,” Bayliss says.
If these plans do come to fruition (and there is a long list of things in the past that Virgin has said were under consideration that came to nothing) it's unlikely that Virgin would go it alone and risk much of its own capital.