Arch Linux is the new giant in the linux world, and there is no way to overlook its importance. Its popularity is growing fast, and there are many distros that have already forked from it. Its appeal lies in its simplicity, efficiency, flexibility and its staying true to the true linux experience. Some of its specialities are:
1) Software repositories: Largest (if AUR is included) among the distros, and the one with the most cutting edge software available because of its rolling release system.
2) The latest stable Linux kernel.
3) Every possible security feature can be added/enabled.
Arch is my new personal favorite. Its difficult for beginners, but if one can follow a guide to set up a running desktop system, getting around with it would not be much different from getting around with any other average distro. For those beginners who really want to use Arch Linux I think a The Perfect Desktop Arch Linux guide at howtoforge would be really helpful. I think it would even be worth while to add a complete section on Arch Linux at howtoforge because Arch is turning out to be a really major distro and is already a hot favorite of many in the Linux community. I wish howtoforge would lead the way for beginners to the use of Arch.
Oh btw, I'd also like to add that the Arch Linux documentation is one of the best.