Vegas 8 is simply a newer version, with some new or improved features. You can find a short review
here. There are many other reviews, simply search with Google for "Vegas 8 Review".
Vegas 8 also supports Vista, while Vegas 7 only supports Windows XP. (Not that I would care, I have no intentions of using Vista for video editing.)
thanks marc looking at prices here in france the software is 700 euros. looking at us prices its only 500 dollars so i think i will buy in the us as the euros is stronger than the dollar .it make sence .steve