OASIS lists following specifications and standards activities related to coordination of messages/transactions, especially in the Web Services arena:

• Business Process Execution Language for Web Services (BPEL4WS)
• Business Transaction Protocol (BTP)
• OASIS Asynchronous Service Access Protocol TC
• OASIS Web Services Composite Application Framework (WS-CAF) Technical Committee
• W3C Web Services Choreography Working Group
• Web Service Choreography Interface (WSCI)
• Web Service Composite Applications Framework (WS-CAF)
  • Web Service Context (WS-CTX)
  • Web Service Coordination Framework (WS-CF)
  • Web Services Transaction Management (WS-TXM)
• Web Services Choreography Description Language (WS-CDL)
• Web Services Conversation Language (WSCL)
• Web Services Transaction Framework
  • Web Services Atomic Transaction (WS-AtomicTransaction) [replaces WS-Transaction-V1, Part I]
  • Web Services Coordination (WS-Coordination) [Version 2]
  • Web Services Business Activity (WS-BusinessActivity) [to replace WS-Transaction-V1, Part II]
  • Web Services Transaction (WS-Transaction) [Version 1]
  • Web Services Coordination (WS-Coordination) [Version 1]
• WS Choreography
• Related Work (not further abstracted or referenced):
  • Business Process Management Initiative Specifications (BPML, BPMN, BPQL)
  • Business Process Specification Schema (BPSS), including:
    • ebXML.org [ebBPSS] and Business Process Specification Schema v1.01
    • UN/CEFACT Business Process Specification Schema Project and UN/CEFACT's ebXML BPSS V1.09 Review Draft
  • OMG Business Process Definition
  • Workflow Standard XML Process Definition Language (XPDL)
  • Web Services Flow Language (WSFL)
  • XLANG

Update: A summary of current state of various standards from W3 mailing list. [via Web Services Strategies]