[sageikosa]

Yes. "For how long" is the operative question. While still affected by gravity (at about 9m/s Earthward) the forward velocity of the ISS's frame of reference is balanced to maintain orbit. At the 0.5m/s (or so) velocity delta in whatever direction chosen, it will take some time for orbital decay to alter the orbit of the jumper.

Things burn up on re-entry because of the tangential speed of the craft (laterally through the increasingly thickening atmosphere as distance to ground increases), not because of the plummet composition of the velocity vector.

If someone could manage a strait jump from that height without forward velocity (in relation to the Earth's rotating frame), I suspect they'd be in freefall (without a normal terminal velocity) until they hit the atmosphere, at which point they'd probably be going pretty fast (9m/s for a few hundred kilometers adds up) and would have some severe heating issues to deal with.

[pyre]

9m/s is velocity. How does this 'add up' over a distance?

[gvb]

That is a typo, it should be 9m/s^2 http://en.wikipedia.org/wiki/Earth%27s_gravity#Altitude (gravity at the earth's surface is 9.8m/s^2, the link states it is 90% of that at the ISS).

[sageikosa]

Yes, that one: (9m/s)/s. Less a typo on my part and more of a "brain-o".