I took a few notes at the Vocaloid panel at Anime Expo last year. It was MCed by Masaki, a person who is quite familiar with the Vocaloid community in Japan and who actually knows many of the authors of some of the more popular Vocaloid PVs. Here is what he had to say about Hello, Planet -

The creator of Hello, Planet, sasakure.UK, composed the chiptune music and drew the NES-style artwork himself.

Sasakure has seen the comments on YouTube and noticed that some people think that the video is very cute. In reality, it is actually a very sad story - "In Hello, Planet, Miku wanders a world where all life has died, calling good morning to everything as she searches for her loved one. When she dies at the end and goes to heaven she meets her loved one and the tears she sheds give birth to new life and new hope to the lifeless world." The message for the video is "be sure to treat yourself and those you love well."

There is actually a special meaning to the final score of "105900" at the very end when Miku is ascending to heaven - the 10 can be read "ten," the 5 "go," and the 9 "ku" - tengoku or heaven.

An animated version of Hello, Planet was just uploaded to YouTube today. It's an awesome take on the original, so check it out!

Hello, Planet is actually a sequel to another video named WANDERLAST. According to Masa, the video is essentially a message left by Miku's lover to the world. It pretty much says - "I don't like when my favorite song ends, so I always stop listening before the finale. That way, the song continues in my heart forever."

According to Mi's Vocaloid Log, Sega announced that the first download pack for Hatsune Miku: Project DIVA for the PSP will contain nine new songs along with a Hello, Planet game. Whether or not it lives up to the video remains to be seen, but I guess it's better than nothing.