I was a little slow on the uptake, but the situation with Iris Zero is that the illustrator, Hotaru Takana, has been recently hospitalized due to sickness. The manga is on a temporary hiatus, though it is not known whether Hotaru Takana will be returning to continue it. The manga serialization will stop on chapter 29 as a result.
For more information from the direct source, visit the mangaka’s blog: http://usachu.seesaa.net/article/277420285.html
(Use Google Translate)
To all those who have been looking forward to a release from IZ, we apologize, but this is now out of our hands.
If it picks back up, you can be sure we’ll be the first ones to scanlate it.
EDIT: It has since been noted that Hotaru stated on her (I’m pretty sure it’s a she -.-) Twitter that she will be returning after she has recovered. So give it some time, soon there’ll be more Iris Zero for all.