Starting October, Shugo Chara Egg will have a new lineup consisting of three members – Saho Akari, Fukumura Mizuki, and Maeda Irori. The fourth member will be selected through an audition:
The lineup change probably occurred because S/mileage members needed to focus more on their group, maybe because they are going to debut soon or because they are working on a new single.
The group might probably just continue singing a cover of the Guardians 4 songs, or they might release some new singles of their own, although that is unknown at the moment.
The two new members, Fukumura Mizuki and Maeda Irori
The show is also going through a renewal around that time, so hopefully it doesn’t affect the group that much. I’ll update when the fourth member is selected.
EDIT: Quote from ANN about the new show and what the girls are going to be doing (Original Article HERE):
“In addition to the anime, Shugo Chara Party! will have regular appearances by the Shugo Chara Egg! female idol group as program hosts. However, the group will have a new lineup: Mizuki Fukumura as Amulet Heart, Akari Saho as Amulet Spade, and Irori Maeda as Amulet Clover.
An open audition will be held for the fourth member, Amulet Diamond. The winner of the audition, which is open to unsigned girls in elementary and junior high schools, will perform as part of the group and appear on the Shugo Chara Party! program. The group will sing the theme song of Shugo Chara!!! Dokki Doki as well.“
This might turn out to be interesting, a combination of live action and anime for the show with the members of Shugo Chara Egg as hosts for some live action segments and a new 4th member which could eventually become an H!P Egg if she is recieved well. Hopefully we find out what happens when the show airs in October.
Hello!SayuNii 
ah~
i really like irorin, but since there has already been a former shugo chara egg, no one else looks quite right in those costumes >.<
i wish they can get different outfits :/
but i look forward to the group and the new members :)
I don’t like these two new members. The role doesn’t seem to fit them as well as it did Yuuka and Kanon.
Personally, I can’t stop thinking it’d be better for Mizuki and Irori to switch roles…
Irori has more of a “Ran”-type feel, while Mizuki has more of a “Su”-one. XD
Irori and Mizuki dont really seem to fit the role of Amulet Heart and Clover i dont really know why but it doesnt seem right *tear* maybe akari will get more lines and become leader now ^^
What? Another line up.
I approve of the change.
Can girls from other countries, but not from japan join in Shugo chara egg adution?
I think the only requirements are the age, the ability to go to Japan for lessons, which would probably mean living in Japan and speaking Japanese.
I don’t think there is a nationality restriction, but the age is probably the most important qualification, they have this for age requirement:
小学1年生～中学３年生の女性
That means that they are looking for someone young for Amulet Diamond. But so far the only important requirements are the ability to live in Japan to take the lessons, knowing Japanese and the age.
But if you want to see more information you can try the official site:
http://www.up-front-egg-audition.com/
Hope it helps ^_^