It looks like Adobe have finally released a QTP plug-in for testing pdf (acrobat) files and applications.

Previously, you had to get the full Acrobat product costing around 500 to do this.

You can find it here:

NOTE - you will also need Acrobat Reader 9.2:

Please provide feedback to us all here if you try this, as I have only used an early beta release of this myself.