You can import and play them back by updating to Mac OS X 10.9 and using iMovie (v10 or later).
Apple iMovie versions ‘08, ‘09 and ‘11 do not support the AVCHD 2.0 codec. This codec encompasses AVCHD footage recorded at 1080/50p and 720/50p. Therefore, AVCHD recordings in these two progressive formats are not compatible with the iMovie software. You may, however, still be able to import videos from the camera to the computer with iMovie by recording videos at either 50i or 25p.
An alternative, third-party software called ClipWrap has been known to support the 1080/50p and 720/50p formats. Visit http://www.divergentmedia.com/clipwrap for information about the ClipWrap software.
NOTE: For further information and help with iMovie, go to the Apple iMovie Help website or contact Apple.