Feature Not in C++0x Remarks
Dynamic Libraries  
Modules  
Special Mathematical Functions An Independent Technical Report
Decimal Floating Point An Independent Technical Report
Thread Pools TR2?
Read/Write mutex Likely for TR2; likely model is Boost.Thread's shared_mutex
Lock-Free Data Structures  
File System Library To be in TR2; model is Boost.Filesystem
Date/time (beyond C++0x's std::chrono) TR2?; likely model is Boost.Date_Time
Networking Library TR2?; likely model is Boost.Asio
lexical_cast Functionality available in Boost.Conversion
Improved IO (e.g., faster, memory-mapped) Boost.Interprocess supports memory-mapped files
Programmer-Controlled GC  
Range-Based Algorithms TR2?; likely model is Boost.Range
volatile with acquire/release semantics  
ABI  
Thread Cancellation/Interruption  
Thread Priorities  
Concepts  
reference_closure Shown to be unnecessary; std::function suffices.
C99 VLAs Proposed for TR2 as "Dynamic Arrays" (N2648)
Features not noted otherwise may be the subjects of their own TRs.