Subscription customers of plain AutoCAD 2009 can log on to the Subscription Center and download Subscription Pack 2. This pack improves PDF output (long overdue and very welcome) and adds the ability to attach PDF files. That’s welcome too, but is of largely academic interest right now because of a total lack of interoperability. Unless you only ever provide your drawing files to people who also have plain AutoCAD 2009 with Subscription Pack 2, they won’t see the PDF underlay. However, round tripping is supported, so when you get the drawing back the PDF underlay will reappear.

Here is a brief summary of the features, taken direct from the download page:

PDF Underlays
Now you can import PDF files, attaching them as PDF underlays. Once you attach a PDF underlay, you can use a variety of tools to snap to lines and objects, control the display of layers, move, scale, rotate, and clip the PDF underlay.

PDF Output
Key improvements have been made for publishing PDF files. File sizes have been reduced, making it easier to share designs. TrueType font support has been added, giving you control over precisely how your fonts are displayed.

This bonus pack is only available in English for AutoCAD® 2009, although, if desired, it can be installed on localized versions of AutoCAD 2009. If installed on a localized version of AutoCAD 2009, all new and related commands display in English only.

As usual, read the readme first, which contains much fuller descriptions of the new features.