The nostalgia, IMO (and speaking as a hobby collector of the original AD&D stuff), is for the original books after all, not reprints of them. The original books can be had for very reasonable (in most cases less than WotC would be charging for reprints) on Ebay as long as you're not looking for collector quality stuff - I don't think I've paid more than $15 for any particular book that I've re-bought and all are in very good condition. Plus I get all the "flavor" 30+ years has added to these, including an original MM in which somebody colored in most of the monsters. Good deals just require patience and perseverance.

As for the reissuing the original game books, it would open a pretty big can of worms in terms of residuals and such - I think WotC learned its lesson when it released the original Dragon compilation CD and got hit with a ton of royalty fees.