According my last calculation, about $980m, but it was some months ago. Anyway, I do not think that number has changed substantially.
That number would be taking into account the record in UK and $300m in US. If we consider that Spectre can drop about $50m in each market relative to Skyfall, we would have that Spectre would be doing about $880m. Even considering that Spectre can sell the same amount of admissions in the rest of markets than Skyfall (mainly France and Germany), what I think is unlikely, it needs another $120m increase in Latin America / China to get the billion. There are chances, but I see it difficult.