We've just released Test::Harness 3.00. It's a complete rewrite of Test::Harness with a more modular architecture that should make it easier to write custom testing tools.
In no particular order here are some of the things that have changed:
And in alphabetical order some of the people who made it happen:
Development on Test::Harness continues. There are a number of proposals on the Test Anything Wiki and at least some of them will make it into future releases. If you'd like to follow progress more closely - or offer some help - you'll find the Test::Harness developers on the TAPX-DEV mailing list or on #toolchain on IRC.