It's true. Virgin is a very trusted and respected brand.
No whether it deserves to be is open to debate (for the most part, I'd say yes) but that's a different discussion.
Seeing Virgin on the side of the ECML trains is bound to be seen as a good thing by almost everyone.
I would rather say that Virgin is a 'successful' brand. Which Stagecoach obviously think is worth paying for.
They'll need a 'virgin boost' in order to overcome the rather large financial hurdle of having to pay seriously increased lease charges for the IEPs.
I suspect the brand thing will be handled very carefully. There will be modest Virgin badges slapped on the Mk4s, and then the IEPs will be introduced in full Pendolino livery with a big fanfair including RB himself claiming responsibility for the 'fabulous new trains' with his fingers firmly crossed behind his back in case someone loudly points out that he had been forced to use them by DfT! Credit will be claimed for just about everything (including work that NR completed before the franchise was let) and the Sec of State will say what a fabulous deal the taxpayer has got (again).
Sorry, I feel that Virgin did a great job in forcing Railtrack into a deal on the WCML upgrade, but after that they have not achieved much more than you would expect from all that investment. The ECML is a much tougher proposition.