Perl 5.10.0 is available here. Also with the torrent file.
You might want to see What’s new for perl 5.10.0, for me, the most important thing is Named Capture Buffers(1) 
And here are some things about performance:
- In-place sorting: Sorting arrays in place (@a = sort @a) is now optimized….
- Lexical array access: faster
- Weak references are cheaper: Weak reference creation is now O(1) rather than O(n), deletion remains O(n)….
- sort() enhancements: faster and memory usage reduced
- Regular expressions optimisations
And known problem(s), maybe solved in future (5.12):
- UTF-8 problems: The handling of Unicode still is unclean in several places, where it’s dependent on whether a string is internally flagged as UTF-8
Also bundled with some new modules, such asCPANPLUS and encoding::warnings 
Let’s wait and see when it will in ports.
Notes: the discussion thread is here. Thanks to Rafaël Garcia-Suarez
- Just like most recent programming languages do (e.g. C# .Net) [back]