But that's what they said themselves. Have you seen this Brian Thompson's introduction of PTC Creo 3.0 on PTC Live Global? At this point he talks about capabilities of Unite Technology in case of "consolidation": https://www.youtube.com/watch?v=RhgALjV0Bm8&feature=youtu.be&t=10m00s - at 10m30s he talks openly that open/import capabilites are free of charge. The whole Unite section of the presentation is here (it's about 15 min time): http://youtu.be/RhgALjV0Bm8?t=2m15s
PTC will charge for extensions that allow saving/exporting to foreign formats as well as updating foreign files' geometry after changes made in native CAD (for example, when you put CATIA part into yur assembly, then someone modifies that part in CATIA and you'd need to update geometry to reflect those changes - then you need additional extension).