The site says to expect Daily Weekday Updates. Hmm.

Also, I wouldn't write off the list of musicians as just fluff. I mean... this could be a clue to what may be represented in the game. The man even says:
This is dangerous. It's a little risky
Then look at the first name on the list: some guy from Konami who is credited for Metal Gear music. Now, if we go by these clues, we can assume/hope/speculate that people that who are brought in from other companies for music may be contributing music from games that they have worked on. Also, people from within Nintendo who have worked on Nintendo games may be contributing music from games they've worked on.

And if the music from these games are going to be there, then there *has* to be something from that game within Smash Bros--be it a character, stage, trophy or whatever.

I'll post the list in quotes. It's a little weird to read. All emphasis such as Underlines and Bolds are my own, for some notable non-nintendo people/games that we didn't know about already.

My Rankings:
Underline= !
Bold= !!
Bold & Underline= !!!

One last note before the list: The last person listed, Yuzo Koshiro, was the composer of the original Sonic the Hedgehog. CURIOUS as to why they didn't include that credit beside his name...

-Akihiro Honda (Konami Digital Entertainment Co., Ltd.)
Metal Gear Solid 4 Guns Of The Patriots / Metal Gear Solid Portable OPS

-Arata Iiyoshi
Pokémon Mystery Dungeon / beatmania II DX

-Asuka Ohta (Nintendo)
New Super Mario Bros. / Yoshi Touch&Go

-Hajime Wakai (Nintendo)
Pikmin series / Star Fox series

-Jun Fukuda (grasshopper manufacture inc.)
killer7 / contact

-Kazumi Totaka (Nintendo)
Animal Crossing series / Yoshi series

-Keigo Ozaki (GAME ARTS Co.,Ltd.)
PROJECT SYLPHEED

-Kenichi Okuma
Melty Lancer series / Welcome to Pia Carrot!! 3

-Kenji Ito
ROMANCING SAGA series / CULDCEPT SAGA

-Kenji Yamamoto (Nintendo)
Super Metroid / Metroid Prime series

-Kentaro Ishizaka (HAL Laboratory, Inc.)
-(nothing credited)

-Koji Hayama
Cho Aniki / Ape Escape 2

-Koji Kondo (Nintendo)
Super Mario Bros. series / The Legend of Zelda series

-Masaaki Iwasaki
MOTHER3 / Chelnov (Genesis)

-Masafumi Takada (grasshopper manufacture inc.)
killer7 / GOD HAND

-Masato Kouda
Monster Hunter / Devil May Cry

-Michiko Naruke
Wild Arms series

-Minako Hamano (Nintendo)
Metroid Fusion

-Motoi Sakuraba
Golden Sun series / Mario Golf & Tennis series

-Noriyuki Iwadare
GRANDIA series

-Ryoji Yoshi tomi (Nintendo)
WarioWare, Inc. : Mega Microgame$!

-Seiji Momoi
METEOS / The Glory of Hercules III - The Silence of Gods

-Shogo Sakai
(HAL Laboratory, Inc.) Super Smash Bros. Melee / MOTHER3

-Shota Kageyama
Luminous Arc

-Takahiro Nishi (GAME ARTS Co.,Ltd.)
GRANDIA series / PROJECT SYLPHEED

-Tomoko Sasaki (TOKIOHEIDI)
NiGHTS

-Toru Minegishi (Nintendo)
The Legend of Zelda: Twilight Princess

-Toshiyuki Sudo (Nintendo)
Everybody Votes Channel

-Tsukasa Masuko
Star Force / Magical Starsign

-Yasufumi Fukuda
Kamaitachi no Yoru 2

-Yasunori Mitsuda (PROCYON STUDIO CO., LTD.)
CHRONO TRIGGER / XENOGEARS

-Yoko Shimomura
Kingdom Hearts series

-Yuka Tsujiyoko
Fire Emblem series

-Yusuke Takahama (TARGET ENTERTAINMENT INC.)
Digital Pinball series

-Yutaka Iraha (GAME ARTS Co.,Ltd.)
SYLPHEED series

-Yuzo Koshiro (ANCIENT)
ActRaiser / Street of Rage