I look at it this way:

Ever since '05, there's been lots of clamoring for a complete I-VI saga boxset, and that's exactly what this blu-ray set will finally deliver. With the help of deleted scenes, this will sell fairly well. It may not do comparable first day business to the '04 set in terms of number of copies sold, but the doubtlessly huge price tag from the extra three prequels will make up for it.

After that, well, I really don't see what else there is to dip with. It looks pretty clear to me that we're seeing a repeat of what happened with these movies on dvd.