Awesome new features include:
* new form-based authentication
* encrypted passwords
* comment system
* unlimited levels of dependency per task
* various administration bugfixes
Read the changelog for all changes... The biggest change is the new admin section, the rewritten javascript, and the color changes. You're gonna like it. Trust me.
that last news bit was a total lie! Download 0.5 and get tracking. Take the demo for a spin. Use the Sourceforge tracker if you have any trouble.