The remastered DVDs do have new interview featurettes. Otherwise, the only difference is on the Halloween disc. It did have You're Not Elected as the bonus episode; now Elected has been released with He's a Bully, and Great Pumpkin is paired up with It's Magic, Charlie Brown.
I haven't watched any of the new ones to see if the remastered image quality is any better. I may buy the remastered versions with changes, but I'll wait on the others. I've got most of the specials on the original DVD releases, so I'm not in a hurry to replace them, unless the image quality is really improved.
You can see some screen comparison on the review here -- http://www.dvdtalk.com/reviews/34854/peanuts-holiday-collection/
Look for the links below 'Screen Comparison Gallery - Paramount (2000) vs. Warner Bros. (2008)'.
It certainly appears like they remastered the specials from the original cells - as the colors are vibrant, but not glaring. The Paramount version, while as sharp as the Warner Bros version, appears like it was remastered from a slightly dull VHS master.
Though, you might want to hold off on purchasing 'Peanuts Holiday Collection'....
One pleasant surprise I just found out is that a new DVD set with six early specials are going to be released in July 2009 -- the chronologically sequenced 2-DVD Box Set 'Peanuts: 1960's Collection' - including remastered versions of "A Charlie Brown Christmas", "Charlie Brown's All-Stars", "It's the Great Pumpkin, Charlie Brown", "You're in Love, Charlie Brown", "He's Your Dog. Charlie Brown" & "It Was a Short Summer, Charlie Brown".
I'll be happy if they can continue with a 'Peanuts: The early 1970's Collection', To me, the specials lost a lot of their magic with Vince Guaraldi's passing after "It's Arbor Day, Charlie Brown". One forum post indicated that a '1970's collection' will be released in 2009, though I can't find any official notice.
I was going to complain about the prices of 'Peanuts Holiday Collection' and the earlier DVDs, but this 1960's set is a bit less (per special) than older ones. It also wasn't very favorable to have to purchase lesser specials not in chronological order. Right now, I guess the only thing to 'complain' about are the lack of background features for each special (though there is a feature about Vince Guaraldi included in 'Peanuts: 1960's Collection'). I'd rather live with the minimal bonus features than have lesser specials included.
I don't have any of the specials on DVD due to the excessive prices with only 2 specials per DVD. The above set will be a no-brainer! Sadly, they didn't chronologically release all of the specials in the first place, though that would leave little sales for the lesser later specials. Hopefully WB continues this, so everyone enjoying the later specials will be able to obtain them.
Here's more info on 'Peanuts: 1960's Collection' - http://www.dvdactive.com/news/releases/peanuts-1960s-collection.html (A note on the image implies that there is a website for the set, but I can't find it) http://www.tvshowsondvd.com/news/Charlie-Brown-Peanuts-Specials-Peanuts-1960s-Collection/11460 http://www.digitallyobsessed.com/showrelease.php3?ID=11514 http://sandboxworld.com/peanuts-1960s-collection/
One other thing I found is that "A Charlie Brown Christmas" will be out on Blu-Ray in 2010. http://www.tvshowsondvd.com/news/Charlie-Brown-Peanuts-Specials-Charlie-Brown-Christmas-Bluray/11650