We know that Premiere Pro CS4 does not support XDCAM and AVCHD formats because, unlike most professional video editing softwares, it doesn’t export them (you have to buy very expansive Mainconcept plug-in to do it).
This problem is increased by another one, which is even worse : unlike for example Edius Pro and Final Cut Pro, which include for free essentials intra-frame editing codecs (Canopus HQ for Edius and ProRes for Final Cut…) to correctly edit HD videos (XDCAM, HDV, AVCHD…), Premiere Pro CS4 does not : in order to edit HD videos with Premiere Pro CS4 (except P2 from Panasonic which is supported by Premiere) , no choice but to buy Cineform codec whose price is 499 $ minimum (add on 2009 10 07 : 129 $ for HDV and AVCHD) ( CineForm Inc ) !!
It was important to communicate this information which shows Premiere Pro CS4 only supports non-HD formats (+ P2 from Panasonic) (Add on 2009 10 07 : and HDV !), because it is not said at all on Premiere Pro CS4 documentation.