Bethesda just told VG247 that Brink's now-confirmed fall 2010 release date is necessary simply in order to ensure the game's "ready".
The Splash Damage shooter was shown publicly for the first time in a gameplay video last night, which revealed the revised date. Up to now it's been pegged for spring 2010.
"The release date for Brink is, indeed, fall 2010," said a rep by email.
"That's when the game will be ready for everyone to play. Hope everyone enjoys the videos we'll be putting out this week for folks that didn't get to see the Brink demo at E3/PAX/QuakeCon/GamesCom/etc."
The movie last night showed the very first part of the presentation, where SD boss Paul Wedgwood demoed the game's SMART movement system. The rest of the demo showed proper, mission-based gameplay and a ton of features, so keep watching.