There's a misconception about video editing when it comes to a fast / high-end computer. Nearly all mid-level machines can do video editing with ease. Having the most powerful computer usually comes down to transcoding and encoding when talking about video editing and not the actual editing process itself. I have an MFA in film editing and have been using AMD products for a while now, I currently even have an AMD FX-8350 with an AMD 7950 GPU.
Speed of video editing really comes down to your hard drive and memory (although CPU is a big help here too). The more memory you have the less likely it will use the virtual memory from your hard drive (which will really slow your computer down) and the faster the hard drive is (where the footage is stored and being imported / edited from) the snappier your editing will be. I highly recommend an SSD before anything else. If you're going to be editing from external drives and not editing from your local drive, I suggest getting an SSD or HD firewire 800, e-sata or USB 3.0 (I do not recommend usb 2.0, it will be very slow when editing).
If you're looking to cut down encoding or transcoding time then the higher end Core i5 or Core i7 will be a little bit faster according to some benchmarks but other benchmarks have the FX-8350 on par with the i7-3770k. Also keep in mind, if you're using Adobe products, Adobe is now beginning to optimize their products for AMD based systems now, especially since the new APU architecture is out.
I use the FX 8350 for video editing, adobe after effects and music - it works flawlessly for me
Hope that helps!