I think a File Viewer could be really handy to quickly browse files.
The Preview frame could be displayed at the top of this pannel (which could be displayed on the right) and a simple Browse button and fileview would let the user choose the folder that contains SHPs, VXLs, etc.
Mock-up image:
![](http://img11.hostingpics.net/pics/457478OSSHPBuilderfileviewer1.png)
Of course, this pannel could be enabled or disabled in the "View" menu.
What do you think ?