Can QuickTime play AVCHD files?
Also, why is QuickTime 7 the latest info on their site, yet I see QuickTime 10 (X) on my Mac??
Last time I checked, QuickTime Player won’t open or play AVCHD files (.MTS). You can import them into iMovie and Final Cut Pro/Express, but that actually does a recompression of the files before you are able to play them. Interestingly, they will play the AVCHD movies back in the preview window of the import dialog, which makes you wonder why they can’t just put that into Player?!
QuickTime does support the H.264 compressor – which is the one used in AVCHD – but it won’t play back AVCHD files.
QuickTime 7 or X
When Apple rolled out Snow Leopard, they also released QuickTime X, which rewrote the underlying technologies within QuickTime, though I don't think it dramatically changed the underlying functionality. You can read about that on the Snow Leopard page, but I don’t know why the QuickTime page hasn’t been updated to reflect this….interestingly you have to work to find that information; the search widget on Apple’s site doesn’t bring it up as a choice off the top!