If it is to come today it will likely be released in 4-8 hours. If not, it'll likely be some time next week
I would say just under 6 hours since they tend to release major content updates on Fridays at 5pm CEST so I suppose it'd make sense to be then.. otherwise we'd probably we waiting until next week.
Oh yeah, I still have massive doubts though. We had to wait almost a month between the WCUSA preview vid and the actual update for example.