Rooting phones can be a wonderful thing. With new phones though, there's usually a waiting period after the phone is released before a root comes out. Chainfire surprised everyone when he released a root method for an international version of the GS5 (SM-G900F) before the phone was even available to the public. That didn't help everyone, though. So again, many people got in the mindset that they would have to wait a bit longer to root their nice shiny new GS5. We've been amazed once again though. Less than a day after carriers are releasing the GS5, Chainfire has added more models (six to be exact) to the supported list. Along with the SM-G900F, models supported include: SM-G900T (T-Mobile), SM-G900R4 (US Cellular), SM-G900T1 (Metro PCS), SM-G900W8 (Canada), SM-900H (International Exynos) and SM-G900M (Middle and South America).
Chainfire's root method uses CF-Auto-Root and is claimed to be the "quickest and easiest way for your first root." It's meant to be used in along with stock Samsung firmwares and keeps it as close to stock as possible. After downloading CF-Auto-Root, it can be flashed from your PC using Samsung's ODIN. Your device will reboot in modified recovery, install SuperSU and restore stock recovery, then reboot your phone. Just be aware that doing this does trip your flash counter and flags your KNOX warranty.
As you probably noticed, there are still variants missing. If you've got a GS5 on one of the bigger three networks in the US (see Verizon, AT&T, and Sprint), this method isn't for you. Considering how quickly variants are being added however, it wouldn't be surprising to see those models being added soon. For those of you who already have one of the supported models and you're looking to root your phone, Chainfire's G+ post links to all of the information on XDA Developers. If you want to jump right in, he also has a direct link for download. For those of you who haven't gotten your phone yet but have a supported model, you've got something to look forward to if you're in the rooting mood. And for those of you who don't have a supported GS5 yet, be patient. It probably won't be a long wait.