Ok, so MPEG Streamclip certainly isn't new but it's such a solid piece of software that I feel like I just need to give it a random mention. I broke it out for the first time in a few months the other day, and I was instantly reminded of how much I really appreciate this software's versatility. MPEG Streamclip is a video encoding application for converting to, and from, a boatload of different formats including: MPEG, MOV, DV, MP4, AVI, and others. You can convert raw Final Cut Pro video files (my most often used function), demux VOB files, and easily export screenshots. And it supports DivX, WMV, and FLV with the necessary components, in addition to all of the other standard formats.
The software is along the same vein as ffmpegX, but the somewhat 'easier' nature of MPEG Streamclip is what really makes it shine. Encoding settings are a-plenty and easily tweakable, plus the software is quick, too. Anyway, if you're looking for a complete video encoding package for exporting Final Cut projects, or want to make some quick MP4s for your iPod, or whatever it is you might want to do with the video lying around on your hard drive, MPEG Streamclip is a fine option for your video tinkering and encoding needs. Oh, and of course: it's free.