If you go to The Mark and type "Exploration Town Hall" it will bring up a Powerpoint presentation dated 9/2/15. It gives a timeline of the COST Phase 3 Process Timing:
Current activities: SGL21+ staffing
SGL1-20 staffing: TMT & BU/function meetings to build out staffing models that deliver COST targets
Sept 14 - ELT meeting to confirm SGL21+ positions
Sept 18 - BU & functions complete draft organization staffing plans
Weeks of Sept 21 and 28: Integrate staffing plans, high grading, leadership review and approvals
Weeks of Oct 5 and 12: Expected period for US severance notifications
November 5: US severance process is completed
The presentation also gives detailed information on headcount for Exploration