Ok, let's try to see the major possible scenarios, while having all the most relevant tweets in one place for a better comprehension of what's going on
1. Roundup of the major tweets of the past few hours
Emily Rogers
Neal Ronaghan
NateDrake (DirectFeedGames)
Daan Koopman
Serkan Toto
2. The scenarios with the highest possibilities of happening
1) Announcement of the event AND the event this week: Serkan Toto himself says his source on NX reveal NOT this week is not as good as the one for the SMR tidbits. Also (I want to highlight this is my personal opinion), Emily said that this is going to be an "important week" for NX and that "the investor meeting will answer more questions about it", which could be interpreted as the reveal being a thing this week (announced in the next 48 hours at most, otherwise it's not happening) with the investor meeting being the place where stakeholders will be informed about other aspects of the device, more pertinent to their area (initial shipment forecasts, planning on sales-related initiatives, etc.). However, I must say that statement of hers isn't cut-clear on the matter.
2) Announcement of the event this week and the event next week (again, personal opinion: probably right before the Investor Meeting): this is how Serkan Toto's tweet and Emily's recent statements would not contradict with each other. Technically, the news of when the NX is unveiled is very important, even if the event does not happen this week.
Supposedly, everything should happen before the Financial Results for Q2 FY2017 are released (before October 26th), or at the latest the day before the Investors Meeting (right on October 26th, when the results are released).