Understanding Arch Linux release cycle

I'm new to Arch Linux and perhaps this question has been asked hundreds of times before but I couldn't find an answer, even in the official Arch Linux documentation: https://wiki.archlinux.org/index.php/Arch_Compared_to_Other_Distributions Arch Linux is a rolling release distribution. This is clear to me. But, what happens exactly when a new version of a package is released? Let's use the kernel as an example:
Say a new stable kernel version is available at https://www.kernel.org . For example 3.12.8. Is this version packaged as it is and pushed to Arch repositories? Or: 1. is there any QA loop (testing) before pushing a package to repository? 2. are some patches applied? If I open a shell on Arch Linux and type uname -r, I get 3.12.8-1. Does -1 mean any customization / patches?