Now I'm downloading 13.04 daily build ISO. I have Archlinux but I want to switch to something more stable and ubuntu is the best Linux OS imo (not just a group of packages but rly good OS). Well my question is: What version will the packages be updated to if I run system update? Will it behave as a rolling release distro or will it stop getting new, other than security updates when 13.04 final is released?
From the version 13.04 will get all kind of updates during 9 months [as @aditya said] as it is not a LTS (long term support verion) and i will recommend you using 12.04 LTS to get 5 years of support and in 2014 14.04 LTS is comming so in 2014 you may upgrade to 14.04 LTS for further more five years. NON-LTS versions get full support of all kinds during there first 18 months after release. All kind of updates ETC