What is the REAL benefit of this program - if there is one? Is it appropriate to risk human like for 1) a personal fantasy or 2) an ultimately commercial venture with no significant contribution to the flying sciences?
That's of course difficult to tell at this stage. When I studied aerospace engineering in the 1980ies, the Space Shuttle was just becoming operational. But it was generally agreed, that the next step in manned spaceflight would be something very similar to SpaceShip 2: A small orbiter, launched from a stratospheric carrier plane or reuseable booster rocket. A number of projects were launched by NASA, ESA and some national space administrations (eg. Hermes, HOTON, Sänger,... ) but proved to be too ambitious or expensive. Still I believe that manned spaceflight should follow this route instead of the 1950ies space capsules that seem to be the preferred option right now - not because they are better, but because the budgets don't allow for more.
Therefore personally I welcome Virgin's commitment in this project. Even if at the present stage it is not much more than a funfair ride for some bored celebrities (even Lady Gaga is said to have booked a ticket), the next evolution might be a true spacegoing orbiter. Which then could also be used for science and exploration for which our taxpayers money seems to be too precious right now.