Yes it will, Nintendo just isn't going to say it supports cards that don't exist yet. Which is the same thing every single other company does.
@OP, Sorry everyone's joking, but in addition to what
@KevinX8 said:
GPU: Rumoured to be 256 cores. Either Maxwell or Pascal, though dev units are Maxwell. It's normal for the device to be upgraded from the dev hardware at the last minute though. Games may be able to choose their own clock speed up to an unknown max. Appears to support antialiasing, but Nintendo games don't use it for some reason.
Built in display: Either 720p or 1080p. If 1080, games will either be run at 720 and upscaled, or be able to choose their own resolution. If 1080p, the web browser, home menu etc. will run at full resolution.
TV mode: games are rendered at 1080p
The Switch itself appears to have a built in fan. It's unknown whether the fan is only used when docked
The dock provides passive cooling, and may or may not provide extra power (As in electricity, not GPU power).
The leaked parents show that each joycon has an extra CPU. It's unclear whether this is only used for wireless and motion control, or if multiplayer games will be able to use it for extra processing power for each player.
The leaked parents also show an NFC reader in one (Not both) of the joycons. This would provide Amiibo support.