Looking at the list of DK streamers and comparing those names to the registration list, excluding the verified million-point players, it's looking like this is actually a really good turnout.
Here are the missing folks I see.
Played in the first, but not signed up for this one:Melkon DomBourian
Jonathan McCourt
Not signed up: (but "highly eligible", so to speak)
Andrew Gardikis (showed interest in this thread, but didn't email his entry)
Chris Icenhour
Dustin Meyers
Eric Howard
John Hunter
Phil Tudose
LeoTyr1ck
Kaayla IllusiveFX (Daniel would know if she is planning to)
Youmee Im
Not likely to sign up: (in my opinion)
Chris Mansfield
Glen Updike
Ken House
Phil Timmons
Tim "Mary McManus" Sczerby
Hopefully a few more people among those names will join.
Otherwise, I think every Donkey Kong player out there is either ineligible, already signed up, signup is pending (Mitch), or at least aware that it's happening.