Human Rights Watch will almost certainly confirm the obvious- in the shadow of the northern and southern rebellions, there has been a massive crackdown on the press, as has been chronicled extensively here and elsewhere (but why go elsewhere?). Leaving aside the hideous moral implications or stifling press freedom, the crackdown is strategically bankrupt for the government. This isn't Saddam's Iraq, for a couple of reasons. Following unification, Yemen saw a lively and largely free press flourish- there were restrictions, but there was also debate and criticism. The people are used to that, and the closing of papers and shutting down of circulations only feeds into the central narrative of the three rebellions: that the government is illegitimate.
Additionally, one can no longer hide a shutdown; there is just too much information available. Salih is shooting himself in the foot. No one will think the southern issue has gone away. You can't hide it anymore. In the name of "preserving unity", they are only opening up the gaps even further.