This story about travelling in Niger, by the Xinhua press agency, "No more convoys under military escort in order to travel in the North", is highly significant, if it's entirely true. It says the routes radiating between Agadez and Arlit in the north, between Agadez and Abalak (on the route to Tahoua and Niamey) and between Agadez and Aderbissinat (en route to Zinder and Kano, Nigeria) are all open to the free movement of vehicles, without the need to travel in convoy with a military escort.
There's enough detail about the fact that it was a "unilateral decision of the governor of the Agadez region", about the "joy on the faces" of local people and especially businesses – which had been limited to one convoy every three days and who can now operate as they like – to make it sound completely credible, even though it comes as a surprise. The note about the authorities not recommending travel at night adds to the sense of normality. Interestingly, although the article refers to "the horrors" of the Tuareg rebellions, it makes no reference to AQIM (Al-Qaeda in the Islamic Maghreb), merely referring to "other forms of banditry".
Presumably, travel to the south of these routes remains straightforward. What it means for the current safety of travel north of Arlit – to Assamakka and Algeria – or indeed northeast past the Ténére Tree and on to Bilma, I have no idea. I think you wouldn't get a sense of that until you were actually in Agadez.