Hey Yves,
I use Premiere Pro CS3 to edit my EX-1 stuff … and it works using just the mp4 files. You have to update to 3.02 to do this, and the performance is great. The other option is to purchase a plug-in from MainConcept or other mpeg utility, if you’re editing PP2, and on my computer (dual core 3 Ghz Dell), that didn’t work so well.
Scott