With Snow Leopard we're also being introduced to QuickTime X (pronounced 10, as per OS X). Breaking away from the QuickTime of old, QuickTime X comprises a brand new platform and player. There's a number of changes behind the scenes, but for those non-developers among us what really matters is that a QuickTime Pro license is no longer needed for QuickTime to be useful.
You only have to play a video to see things have changed. As you'd expect, playback controls float above the video, but click play and move the mouse pointer off the window and not only to these controls disappear, but so does the title bar, leaving a floating windows of just video which looks pretty snazzy I have to say.
More functionally, the Trim interface familiar to users of iMovie, or more recently the iPhone 3GS makes an appearance. Videos can be exported directly to either MobileMe, YouTube or iTunes. That latter option presents the further three options of re-compressing for a computer, the iPhone or an Apple TV. In addition to movie and audio recording, QuickTime now offers screen recording, with audio commentary of course.
Some of those aforementioned background changes are probably going to annoy a number of users. QuickTime X has absolutely no support for plugins, which by extension means any unsupported codecs or file wrappers will remain so until Apple rectifies that situation. If you want to play those home videos you happened to save as XviD-encoded MKVs, you'll be stuck with VLC for a while longer yet.
A number of other lesser refinements have been made, too. Preview is significantly faster in Snow Leopard, VoiceOver is notably enhanced, you can use a multi-touch touchpad to draw chinese symbols - a tad gimmicky, maybe - and iChat video bandwidth is reduced from 900kbps to 300kbps. As you might think form ths myriad of changes, if Apple's intention was - as stated - to simply make a better Leopard then it's far exceeded that remit. Snow Leopard is faster, has a smaller footprint and, thanks to the frameworks provided, should lead to better apps being developed for it henceforth.
Snow Leopard is indisputably the best operating system Apple has ever produced. There's absolutely no reason not to recommend it and that's about as high an accolade as an operating system is likely to get.