What kind of output do you want? HD? SD? Widescreen SD? The way I understand it, you just need to resize your SD footage big enough to make a crop for widescreen. There are some software out there that claims to do this better than the native resize filter in PP. I actually found Windows Media Encoder a better software for upsizing footage to HD, then just import the wmv to PP. Or, resize your HD footage in your SD comp which is a lot easier. Of course, you get pristine footage from your HD source.
Alex