Light theme updated will be automatically in Lucid?

If the package used to install it (assuming it is a package) is in the lucid repos then it will be upgraded. Other themes you have manually installed will be in $HOME so will survive the upgrade no problem.

andy@D420:~$ apt-cache search theme | grep light
light-themes - Light Themes
cairo-dock-data - A light and eye-candy dock to launch your programs (common files)
eterm - Enlightened Terminal Emulator
eterm-themes - Themes for Eterm, the Enlightened Terminal Emulator
highlight - Universal source code to formatted text converter
highlight-common - source code to formatted text converter (architecture independant files)
libhighlight-perl - perl bindings for highlight source code to formatted text converter
lxsession - a lightweight X11 session manager
mythtv-theme-arclight - The arclight MythTV Theme
oroborus - A lightweight themeable windowmanager for X
xfe-themes - A lightweight file manager for X11 (themes)

andy@D420:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 10.04 LTS
Release: 10.04
Codename: lucid

HTH

I ran that command and I got this...

light-themes - Light Themes
cairo-dock-data - A light and eye-candy dock to launch your programs (common files)
light-themes-fixed - Light Themes Fixed

So, the package are in Lucid Repos, isn't it? And they will be upgraded when a new releases be out?

The packages are reviewed every 3 months (or is it 6) anyway they will come down when the MOTU update them.

andy@D420:~$ apt-cache policy light-themes
light-themes:
  Installed: 0.1.6.5
  Candidate: 0.1.6.5
  Version table:
 *** 0.1.6.5 0
        500 http://gb.archive.ubuntu.com/ubuntu/ lucid/main Packages
        100 /var/lib/dpkg/status

Its in the main repo so will be upgraded if you jump from karmic to lucid.

Thank you very much!