We’re officially getting the new patch tomorrow. 4.0.1 brings the new talent trees, Emblems are officially gone for justice points, as well as a new Glyph system.
The patch notes can be found here .
As expected, Blizz is throwing some extended maintenance at us that actually starts midnight PST. You may as well wait to log back in tomorrow, as with something this big we can probably expect a delay in many (if not all) realms coming back on time or without difficulty.