I saw an Avid Liquid demo and was impressed. It's pretty cool, but with an unattractive UI and perhaps some bugs that the demo guy tried to hide. It's an all-in-one deal developed by Fast then Pinnacle and recently Avid, so it doesn't understand Avid metadata or have an XML export function to get to other systems, like Final Cut's connect to Discreet finishing systems. But they can export a QuickTime alias from the regular Avid products and play it as regular media.
These are my favorite aspects of Liquid mostly not found in Premiere or Final Cut (or Avid):
1. The feature I liked the most was background rendering, which is really impressive -- and scaleable with hardware support. What's cool is that even complex processes previewed fine quarter screen even before finishing in the background. And you have control over how to delete old render files from the cache. You don't have to render nested sequences!
Hyperthreading allows you to switch to text or e-mail to check on client reviews while playback continues. I think all NLEs should have backround rendering, and hope After Effects will in order to stay abreast of the Combustion and Motion rendering model.
2. Liquid uses native codecs of a file without rendering or conforming, unless there's scaling or other things.
3. In Liquid you can change project properties like frame size anytime, and assign rendering to any appropriate codec.
4. You can add transitions to a selection of multiple clips.
5. View keyboard shortcut layouts in context with a virtual keyboard.
6. Correct or effect a source file, so further instances have the same correction.
7. Color correct by direct manipulation of vectorscope or histogram.
8. Actual 3D effects, like an explosion (think AE Shatter) that can be manipulated in the program monitor. I like the that crop, which includes a nice rounded corner feature, seems to be in the Motion area of Effect controls. Effects can be turn on or off via a timeline context menu.
9. You can have multiple clip bins, and have them open at the same time. When PPro has a patch that adds that feature, I'd be happy to use it.
10. Bins of various types can be shared apart from the project. Effect aliases can be in any bin.
11. There a Liquid desktop, like a master application shell window can hold open bins and individaul clips. Any part of the Liquid desktop can serve as a storyboard space and clips can be edited and previewed individually or as a sequence apart from any timeline.
12. There's a simple backup project function.
13. There's a dynamic timewarp with bezier controls.
14. Audio tracks can be stereo or disbanded quickly to mono in a context menu.
15. In DVD mode both menu and timeline plays out to NTSC (tho that might not work with just Firewire out). This is what I hope for in the next version of Encore.