There is a Code Preview Handler, but it supports only the extensions .cs, .vb, .js and .sql . The source code is available and it doesn't look too complex to create a Preview Handler (well, sort of, I wouldn't know how to do one).
I tried adding other extensions to the Code Preview Handler with the tool Preview Handler Editor but it doesn't work, the preview pane is blank (at least for the .pl files I tried).
Edit: you have also a pack of Preview Handlers here, that support the following filetypes:
* ActionScript (.as)
* ASPX (.aspx)
* C# (.cs)
* CSS (.css)
* Diff (.diff, .patch)
* DOS (.bat, .cmd)
* JavaScript (.js)
* Ruby (.rb, .rhtml, .rjs) thanks to Ivan Porto Carrero
* SQL (.sql)
* VB (.vb)
