Derick Rethans has a new post to his site starting a series of posts about the new features of Xdebug 2.3. In this new post he talks about an improvement that's been made to the output provided by var_dump with more information than before.

One of the new features relates to one of the first things that I added in the original Xdebug: making the var_dump() output "pretty". Xdebug replaces PHP's standard var_dump() function with its own version, as long as the xdebug.overload_var_dump setting is not set to 0. [...] Xdebug 2.3 enhances the overloading of var_dump() with the inclusion of the file name and line number where var_dump() is called at. This has been a long standing feature request.

He provides a few sample screenshots comparing the old and new output formats and mentions another handy setting, xdebug.file_link_format, that makes the resulting filename a link in a browser and lets you customize the format.