Not in a specific order:

• Create WP_oEmbed_Legacy_Controller, possibly removing WP_oEmbed_Plugin (Refactoring for an eventual core merge #35)
• Having the plugin active after merge shouldn't result in a fatal error (Add function_exists check to the plugin #50)
• Inline Docs review (Inline Documentation Review #46)
• Security Audit (Security Audit #48)
• User Tests (User Testing #49)
• Increase usage numbers (Increase usage numbers #54)
• Write a post on Make/Flow about the plugin
• Write merge proposal (Write Merge Proposal Post #52)

Plugin merge window is probably already in a couple of weeks so we should be ready