Spaceship One, going for two of two

The vehicle speed will
be much higher in that situation, and it's not clear to me that the
"feathers" will be sufficient for slowing the aircraft down, nor is it
clear
to me that the vehicle has sufficient heat protection even if the feathers
could serve that purpose.

Mr. Duniho is right on. SpaceShipOne is not designed with any heat
protection. It would not withstand the heat loads of reentry at orbital
velocity and it never will. That's another generation, maybe several
evolutions away. If you need analogies, think of SpaceShipOne as the Spirit
of St. Louis and the orbital craft as the Concord. It is a long way off.
When I interviewed Mike Melvill after his first ride into sub-orbital
space, he explained the feather scheme to me. Feathering the wings has no
direct affect on slowing the vehicle down other than to place the main body
in the attitude of maximum drag, i.e. maximum cross-section normal to the
velocity vector, and provide some limited control to rotate the main body
around the velocity vector.
According to Melvill, the reason the main body is so fat is to have a
very high drag cross-section. At some point of aerodynamic force and
velocity in the decelleration, the wings are moved from the feathered
position to the 'normal' position and roll, pitch and yaw come back into
operation.
The word feathers has been grossly misused by the ignorant media. But
what can you expect from my esteemed colleagues -- especially when one asks
Melvill if they plan to fly SpaceShipOne to the International Space Station.