I think it was the "D&D's Soul Boxed Set". You got one soul of D&D, Monte Cook's lifeblood, as well as E. Gary Gygax's sweat and tears.
There's more:
The Warlock: A spellcaster that casts his spells (or rather spell-like abilities) all day.
The Spellthief: A roguish character that uses his enemies' spells against them
Book of Nine Swords: Abilities that are "once per encounter" rather than "X/day"
New Formats: You already mentioned some, but there are others: New Format for Classes (which I really like) and PrCs (which could be shortened, but gives lots of fluff); In the Monster sections (as well as various other parts): Small sidebars containing information obtainable with Knowledge checks; The magic Item format; Spell format (the little descriptive text at the beginning).
Fantastic Locations: Large encounters complete with full-scale maps (that double as locations for skirmish battles)
Which brings me to: D&D Miniatures: Okay, they're not from the last year or two, and they weren't the first of their kind, but the idea of cheap, prepainted plastic minis (which are anything but dainty - they're used to a much rougher treatment then your average painted pewter piece). The figures serve two purposes at once: You can use them for D&D (and the sculpts come right out of the rulebooks), and you can use its own game for some quick battles on the side, if you can't gather the whole posse.