He does look very good after the fears reported by the doctors in the days after the crash. Certainly no sign of the neck brace you'd expect for the reported basal skull fracture (the injury that killed Roland Ratzenberger). Thank God for HANS.
Actually, its worth reading the HANS article on wiki for a sober reminder that motor sport is dangerous.
http://en.wikipedia.org/wiki/HANS_device -- F1 introduced HANS in 2001 following a single basal skull fracture death in 1994. In NASCAR there were 4 deaths in a 14 month period up to Feb 2001. What is worrying is that many NASCAR drivers resisted the introduction of HANS until that 4th fatality.
To give some context on recovery from a depressed skull fracture (I think that's what Massa's has) , Petr Čech took 3 months to return to football (soccer) after a similar injury.
http://en.wikipedia.org/wiki/Petr_%C4%8Cech#Head_injury
I hope Massa doesn't come back too soon. Possibly start to build himself up in winter testing.... although a cameo at Interlagos might be too tempting???
... but I wouldn't be surprised if headaches and poor vision keep him out until 2011!