UTAU Sakusei started between two roleplayers, Azure and RabidSyndrome respectively, decided that they were going to make their own UTAU characters. Although they didn't know how to (or rather, Azure didn't really know), so the idea was postponed. It was later picked up once again when Azure decided to turn her roleplay character (Mayashima Anju) into an UTAU. RabidSyndrome agreed, and a name was chosen on Thursday, 21st May 2009.
UTAU Sakusei literally means 'sing create' To our UTAUloids, there is nothing special about them. They are literally our 'Singing Creations' that are handled with tender love and care, in hope that they will take flight and preform well on the stage that is the internet.
On the actual day of creation, another joined (Project) UTAU Sakusei, Mari (known as Cheesegirlchu on Youtube) with her own to-be-released UTAU.
The first Sakuseiloid's ACT 1 (Public Beta Release) to be released is Mayashima Anju, created by Azure. Set release date is 11th June 2009.
The second Sakuseiloid to be released is Tsukiko Tarine, created by Mari. Set release date is unknown.
The third Sakuseiloid is actually a set of siblings, one male and one female, both voiced by RabidSyndrome. Karamarune Naka (male) and Naji (female) will be released simultaneously as separate voice banks some time after Tsukiko.
The fourth in the Sakusei line is, most likely, the first crippled UTAU to be designed, named Yuubou Kaneru. Her design was a collaborative effort between RabidSyndrome and Milksake on deviantART, and she will be voiced by Yasachii from the same site. You can hear Yasachii's voice as-is on her YouTube channel.
There are future Sakuseiloids planned, and other UTAU users are expected to join this small project in the time to come.