That's not quite how I've been spending my time with the 5D Mark III, but thankfully James Miller was brave enough to try to get the most out of his camera by tearing it apart. We know that the Nikon did not completely remove the low-pass filter on the D800E, because it still requires the IR filter - but the Mark III seems to have two strong optical low-pass filters in front of the sensor. James explains exactly what he did below, and it is definitely giving his 5D Mark III a lot more detail than before - and he's got some video to prove it.
This is the explanation from James about the specific low-pass filters on the 5D Mark III:
It has two of them. This is just the outer one that doubles as the self cleaning plate. An IR cut filter and 1st OLPF are fixed on the sensor assembly. Not removed here.
The Verge for originally posting this EOSHD who originally posted this from James Miller's Twitter account, and then we picked it up from The Verge. Here are two videos showing footage with that specific low-pass filter removed:
Video is no longer available: vimeo.com/39594898
That looks sharp, much sharper than what I've seen from the 5D Mark III in my testing so far. For good reason Canon put an extra strong low-pass filter into the Mark III to get rid of aliasing in video mode, and that's why it is gone. It does, however, seem to come at the cost of some resolution. One would think that this would be causing a lot of moire, but those bricks seem to be doing fine - and he may only have a problem with other types of fine detail and patterns. He's also got a photo comparison showing a video snapshot with, and without the front low-pass filter. Light differences and possible focus differences aside, it looks a lot clearer.
So is this going to be the solution for all 5D Mark III owners to get the most out of their video? Let's hope not (unless trained professionals are doing it). This will no doubt spark the curiosity of many adventurous camera owners, some of whom will probably destroy the sensitive components inside their cameras in the process. This is not something you should ever, ever consider doing unless you're a trained technician or you have tons of knowledge with repairing DSLRs. Opening the camera removes your warranty, just as with any other electronic device, so you would be completely on your own if you did this.
Will this cause moire to appear? Most likely, though we've been shooting with moire-heavy cameras for years now, and many have just dealt with it as much as possible. From looking at the samples and the video, it doesn't seem like it would be nearly as problematic as the with the 5D Mark II, which might have more trouble with a scene like the one that James shot above. It's certainly interesting, but it's not going to be something you should try unless you've got some money to waste, because results can't be guaranteed, and it's not clear how difficult it would be to put the low-pass filter back in if you are not happy with the results.
It would be interesting to see if video might be improved on the Nikon D800E, but I have to suspect since moire can be an issue on the D800, that the D800E will be even worse for video. This is a fascinating development, so hopefully we can get to see more samples. Back focus is affected by the presence of these low-pass filters, so if you were to do this yourself it would be helpful to have another clear filter put in to replace the one that was removed. My advice, if you want to do this with your camera, would be to send it out to a company that is trained to do this sort of thing - as doing it yourself could end in a malfunctioning camera.