In addition to the brief glimpse at the new SUV, Musk announced a few other details. The SUV likely won't share too much with the Model 3. He mentioned some criticism for not basing the Y on the 3, but explained that he felt it was a "mistake" to base the Model X on the Model S. He said, "It would have been better to design an SUV the way an SUV should be designed, and design a sedan the way a sedan should be designed." This is an interesting statement considering that the auto industry is beginning to move toward modular platforms. For example, Volvo has two modular platforms, one of which is currently in use, and Volkswagen is working on a modular system for future electric vehicles.
Musk also mentioned that the Model Y should show up in 2019, and Tesla is expecting more demand than for the Model 3. The Model Y will also be built in a new factory, since Musk says the Fremont facility is at capacity. Those were the only other details Musk provided, but he hinted that there would be more information at the unveiling of Tesla's semi-truck, which will happen at the end of September 2017.