Capture HD video via HDMI to Thunderbolt

In the previous world of Firewire 400, I used to be able to simultaneously videotape and capture SD footage by going from firewire 400 out to my laptop with firewire 400 or 800 in. This was done by using 'Non Controllable Device' capture setting in FCP. This was a great for creating a backup, and for saving on capture time when I was ready to edit.

I am now shooting witth a Panasonic AG HMC150 which has an HDMI out. I was wondering if there is a way to transfer footage while shooting by going from HDMI out to Thunderbolt in capture mode rather than transfer mode? A simple cable adapter sounds too good to be true, so I am guessing if it is possible, that perhaps I would need a device by Matrox or Black Magic that could perform this task. Of course I could easily fork out $3K - $4K(yah right) for an AC160 or AC130 with dual card readers to run my back up, but my present camera is doing just fine at the moment.

Has anyone tried this yet? Thanks in advance for any suggestions or solutions.