I have a few observations I wish to share so we can all be consistent in testing. I have the fat PS3 80GB model in North America format, so I downloaded native 1080/60p clips from Vimeo in the .MTS file format. I copied the file from the USB stick to the PS3 hard drive to ensure best access. The best clip to test for playback problems is the "Alumapalooza" clip on Vimeo. Here we have the subject talking so we can clearly see the audio sync/playback issues. The clip is here: http://vimeo.com/10706438
Now here is the interesting thing. My TV supports all resolutions to a maximum of 1080/60p. Therefore, I set my PS3 HDMI output to "Automatic" After the handshake, the PS3 outputs the .MTS in its native resolution AND framerate. The result is the clip loses audio sync after a few seconds. HOWEVER... If I set my PS3 settings to HDMI output maximum of "720p" then something surprising happens. The native .MTS file is downscaled by the PS3 to 720p. My TV has a native resolution of 1080p, and it upscales everything to that format, so if I check the TV information, it says it is displaying 1080/60p. So, do not be fooled into thinking that your PS3 is playing smooth video unless it is set to 1080p maximum HDMI video resolution AND your TV is NOT performing any upscaling.
I have also tried re-encoding the test clip with Sony Vegas Pro. If I keep the bitrate BELOW 24Mbps thent he file plays without issue. If I re-encode at anything greater than 24Mbps, the the PS3 loses audio sync.
All this leads me to believe that the fat PS3 is not capable of playing an AVCHD file of greater then 24Mbps bitrate (which would be resonable according to AVCHD spec). It is possible that if you have a slim PS3, a higher bitrate is supported, or that the slim PS3 is actually downconverting to 720/60p to compensate for not being able to play the file of greater than 24Mbps bitrate.
When I insert a video analyzer box in the HDMI chain, I note that the fat PS3 plays the native Panasonic footage with loss of audio sync, but zero frames are dropped. On the slim PS3, frames are dropped, so I don't know if the PS3 is internally doing this or if there is downscaling happening. At any rate, the slim PS3 in North America seems to be altering to stream to be playable although this means that it is not actually the native footage bit for bit.
My conclusion so far is that the only way to watch bit-perfect 1080/60p footage from the Panasonic is to play it back on a good computer, or to play direct from the camcorder itself. If you wish to use Windows Media Player, you can install CCCP codec pack or K-Lite Basic codec pack. Both allow superb bit-perfect playback on a dual core machine of at least 2.2 GHz. Of course Windows 7 does not need any codec packs.