Since version 3.0 Alpha 1, the following changes (and more) have been made:
* New: Gradient Tool supports linear, radial, diamond, and conical gradient modes.
* New: Merge Layer Down command in Layers menu and Layers window
* Changed: A version of the Unsaved Changes dialog is now also shown when closing just 1 unsaved image, instead of the old fashioned Yes/No/Cancel MessageBox
* Changed: Alpha Blending and Anti-aliasing buttons are now split-buttons, with different icon and some descriptive text
* Changed: Shortcut key to open the MDI overflow list is now Ctrl+Q, instead of Ctrl+Space
* If an important installation file is missing, Paint.NET will try to repair the installation instead of crashing
* 256x256 icon format is now compressed, dropping EXE size by 150K
* Fixed: a bunch of crashes that users were reporting
* Fixed: "Load from toolbar" in Choose Defaults dialog did not pick up the active tool