I have been using the render excam ex drop down, it seems fairly peppy,can be read by youtube and plays fairly quickly. Any reason not to use this as an archive format? Is there a way to see the clips in WMP (win 7) and not utilize sony clip viewer?
I still like and use Jpeg2000, but it's not the solution for everyone. It's efficient, open standards, and cheap (free for Vegas users). However, VC-1 (Windows Media Video) and VC-3 (DNxHD) are now also open standards and also viable as archival solutions. DNxHD has the source code available whereas WMV does not, so that makes a difference to me.
Unlike any of these other solutions, Jpeg2000 can be lossless if so desired, though it does tend to make large files that way.... just like any other lossless solution.