You can render out your footage in any format and you want. You can shoot in HD and deliver in letterboxed SD. You can render for the web at any data rate you need. I have been working with an EX1 and like it.
You definitely need some kind of shoulder mount though. It is good in low light and there are no dropouts that I have seen (I have seen digital dropout errors on P2 card footage).
I think you should try to rent one if you can. That way you will see what it can do. The footage looks great.
Bob