Go to sublime text website [http://www.sublimetext.com/3] and get the latest tarball url for your Linux (32bit or 64bit) for example currently it's the http://c758482.r82.cf2.rackcdn.com/sublime_text_3_build_3080_x64.tar.bz2
Download the latest script, and set the executable permissions:
wget -O ~/install-sublime-text.sh http://git.io/jvvG
chmod +x ~/install-sublime-text.sh
And run the command with the url of the latest tarbal as obtained earlier:
cd ~/
./install-sublime-text.sh http://c758482.r82.cf2.rackcdn.com/sublime_text_3_build_3080_x64.tar.bz2