In the latest Tek episode, it was stated that the WRT1900AC has 128GB of flash memory. According to all news reports and documentation online, it has 128MB of flash memory. I'm not sure if this was an oversight or just misinformation provided at the show.
It would be a little strange for a router to have such a large amount of flash memory. Enterprise level routers/switches don't even have that much flash memory.
Beyond that, I am extremely excited about the fact that the WRT series is being brought back and staying true to it's former self. They are openly supporting the open source community, and making it easy to swap out the antennas.
This is a welcomed breath of fresh air considering their line of routers went from external antennas to internal. While some may like the internal antennas for aesthetic reasons, I prefer the external antennas for the range.