Anousak just send me this mail:
On *daily built* images (not beta!) which you can get from
http://www.debian.org/devel/debian-installer, you'll find Lao and
listed in the available language.
Please note that, as many packages need to be uploaded with your
translation work, if you happen to try starting an install in one of
your languages (you can on any machine, at least up to the
partitioning stage, without any risk), it will be mostly in English.
Thanks to Debian maintainer, Christian, who have been working with me
to bring Lao into the Debian Installer and etc.
Debian is the main distro other Linux derivatives including Ubuntu.
If you want to play with Lao Installer, feel free to do so, and
comments are welcome.