I’m admittedly a bit late (a month) to the news , but PHP 5.3 alpha 1 has been released. I’m lucky to have stumbled on the news, because I haven’t followed PHP’s release schedule at all lately, but the 5.3 release is particularly exciting – PHP finally has support for proper lambda closures – now it’s a real language 
New features below, and release notes here:
- Namespaces (documentation maybe out dated)
- Late static binding and __callStatic
- Lambda functions and closures [Ed. – finally!]
- Addition of the intl, phar (phar is scheduled for some more work a head of alpha2), fileinfo and sqlite3 extensions
- Optional cyclic garbage collection
- Optional support for the MySQLnd replacement driver for libmysql
- Windows older than Windows 2000 (Windows 98, NT4, etc.) are not supported anymore (details)
- New syntax features like NOWDOC, limited GOTO, ternary short cut “?:”
Also exciting: significantly better internationalization support, and a PHP archive format – the .phar. The combo of namespaces and the addition of .phar support should allow for much better organization of libraries and applications. I’d love to upgrade WordPress by uploading a single .phar file instead of the hoopla you have to go through now.