Vegas only has a single preview screen. It usually shows the final output preview. If you open the trimmer or preview a clip in the explorer, it will show in that same preview screen replacing the output until you return to the timeline.
This has never been a problem for my workflow but I can see how you might miss it if you’re used to it. Instead, consider all the screen space you’re saving by only having one. There really isn’t a need for two.
As for workflow, I only use the trimmer when I have a specific reason to do so. For normal editing, I just use the timeline so the preview is almost always showing me what would actually be output should I render at that point.
Edward Troxel
