What's new? 

A lot, but here's some of the key new changes so far...

Browser - The Browser has changed (now with category tabs and the ability to delete content on right-click)
Channel Menu - The Channel Options Menu has moved from the Toolbar Menus to the Channel rack.
Channel settings - Have been integrated into the Plugin Wrapper.
Interface - Vectorial user interface. See Options > General Settings > GUI display.
Per Channel Swing - The Channel Settings now has a 'swing multiplier' amount.
Pattern Menu - The Pattern Menu has moved from the Channel rack to the Toolbar Menu and Pattern Selector.
Piano roll - Piano roll Auto-zoom can now we deselected from Settings > General > Auto zoom in piano roll
Playlist - Multiple drag and drop for audio files onto Playlist (from a Windows file browser).
Stepsequencer - Stepsequences are now interchangable with Piano rolls.
VST Plugins - VST plugin installation has changed.