What do you think about dual preview windows? One for the timeline and one for the Trimmer? I would love this feature. I am trying to rally support for this feature for the next release.
I agree this would be good, and I've suggested this feature to SF using the Product Suggestion page.
Why? EditDV/CineStream has dual windows -- one is usually for the Source clip (roughly the same as the Trimmer Window) and the other for the Timeline. It's handy for doing a side-by-side comparison of two clips (or two locations in one clip). CS also uses the two windows instead of Vegas's side-by-side squeezed frames for display during certain editing operations.
I use a dual-PC monitor setup, so have enough screen real estate for another window. And I use the Trimmer a lot.
Another useful thing that CS does that Vegas could emulate is that the picture in the Preview window is updated even if an external monitor is connected, though not while something is actually playing.
I also favor having a separate window to compare the 'source' and 'project' clips, although I think SoFo addressed that with the split-screen feature of the preview window (which was quickly copied by Premiere Pro). That was a truly great feature addition.
All the same, it is, to me, a time-consuming and sometimes confusing process, for instance, to do color correction by trying to capture one screen from the timeline cursor, draw a box, and remember the steps to "pasting" the comparison shot alongside the clip running in preview. I wish it were possible also to select "View > Second preview window" and have the option, as this would allow other operations with two fully functional windows. Maybe the second window could pop up/toggle in the Trimmer window?