PerlSAX2 attempts to replace XML::Parser as the basis for other XML modules. XML::SAX isn't a parser, but it'll select one for you. There are two supported right now, Expat (the C library XML::Parser is based on) and a Pure Perl solution.
That's right, XML parsing in pure Perl. I want to buy Matt a beer for that alone.
What's the big deal about PerlSAX2? As more modules are based on it, instead of XML::Parser, we'll be able to take advantage of the features of different XML parsers. No more being tied to expat! This will, I hope, lead to better performance (we're running into callback limitations with XML::Parser) and quicker adoption of new XML doodads in Perl.
Ultimately, Perl will become the XML language, everything else will wither and fade away, we shall go on to force-feed punctuation-shaped humble pie to the W3C before proclaiming ourselves emperors of the world! Hmm, perhaps too much Pinky and Brain for me. Are you pondering what I'm pondering, Matt?