Update: According to Citadel "we're laying off some employees but not shutting down the entity. This continues to be an ongoing business."
From the front lines:
Everything is over today, exit interviews being done now. Sales and trading started getting the ax at 8:30am. Research at 9am. Credit and banking - part layoffs, part being sold off to another firm. No details on severance yet but rumor is 1.5 months plus pro rated bonus. Options and some trading being rolled into CES.