Hmm. Wiki says this: «I Love the World, also known as I Love the Whole World, is an advertising campaign launched by Discovery Channel in 2008 in promotion of their new tagline: "The World is Just... Awesome".[1] The song used in the ad is a re-writing of a traditional camping song known as I Love the Mountains or I Love the Flowers, sung to the tune of Hoagy Carmichael's 1938 "Heart & Soul", featuring a chorus of "boom-de-yadda, boom-de-yadda".[2]»
Not really confusing at all. They combined the two with the verses taking their melody from 'Heart & Soul' and the 'boom de yada' from 'I Love the Mountains.'
Upvoted for recognizing that the melody is the same as in 'Heart & Soul' but the 'boom de yada' melody is also in 'Heart & Soul' as harmony. Well, it's technically not harmony (my music theory is a little shaky) but it's in the background of the melody. Just listen to the first few measures of 'Hear & Soul' and you'll hear it.
tl:dr All parts of the mountain song melody are in 'Heart and Soul.'
There are actually lots and lots of video tributes to this strip, although this new one does feature a bunch of celebrities. Here's one of the best older ones:
I'm hoping this is a joke that I overlooked, because I think it's rather unlikely that you're going to get an interview with Neil Gaiman jumping up and down on a trampoline and incidentally says 'I love her sister' to one of this twin daughters. Also, I'd hope Cory Doctorow doesn't wear that cape in every interview.
Fair enough (and I had to google Cory Doctorow). I think it's possible then that some clips were specifically recorded for this, and others just caught from other videos.
The clip of Lessig is actually from his appearance on the Colbert Report, where Lessig gives viewers explicit permission to remix, despite Colbert threatening to get "very angry and possibly litigious".
The voice might actually be Lessig purposely recording for this creation.
http://xkcd.com/442/
which tracks the original discovery channel ad:
http://www.youtube.com/watch?v=at_f98qOGY0