September 27th we'll find out, but I've got some fun predictions.
The MCT (or BFS) will not carry 100 crew or 100 mt to the surface of mars. The BFR will be 10m w/ 9 Raptor engines but will soon use 2 F9FT reusable boosters. The MCT will not be reusable, instead it will be left on the surface of mars (engines will be removed for a new future vehicle of martian design each using a single Raptor engine.)
A second generation MCT will only travel from orbit to orbit. A martian SSTO will support operations at the martian end while a stretch Dragon will support earth orbit operations.
The MCT that lands on mars will deliver 500kg per crew to the martian surface when fully crewed (more cargo when less than fully crewed.) It will require 500kg of food per crew in space during the voyage to mars. Water will be recycled but start at 500kg per crew.
It will be refueled in earth orbit massing 100 mt before fueling. Maximum crew will be about 50, not 100 as originally planned.
Update: My mars colony trust will only pay $5m per ticket. 3 FH supply launches will be required before MCT mars departure for a total ticket cost of about $16m per crew. If Musk agrees to contracting the colonists to support property ownership of martian real estate he'll take the $5m (which adds incentive of a cost reduction goal.)