The battery is even harder to remove now and is glued in with excessive amounts of adhesive.
There is no "M7 co-processor" [1] chip in the device - possibly it's just marketing for some part of the A7?
The new fingerprint censor is a bunch of small capacitors. Possible cause for concern if you plan to keep using the fingerprint access for the life of the phone.
[1] http://techcrunch.com/2013/09/15/apples-m7-motion-sensing-co...
Not sure why the iFixit guys jumped to the conclusion that it was possibly marketing fluff. It is an SoC after all, the M7 doesn't have to be a separate chip on the logic board.
I thought the M7 was presented as a co-processor, from Apple.com, which has nothing referring to it as a chip:
> Every iPhone 5s includes the new M7 motion coprocessor that gathers data from the accelerometer, gyroscope and compass to offload work from the A7 for improved power efficiency. [1]
As a co-processor, its probably embedded in an SoC.
[1] http://www.apple.com/pr/library/2013/09/10Apple-Announces-iP...
http://www.macrumors.com/2013/09/20/a7-processor-manufacture...
The SoC may be a multi-die part (like a Tegra 3). We'll get more info on that when Chipworks or someone gets a look at it.
From Anandtech's digging, it does look like the M7 is a thing with its own processor, at any rate: http://www.anandtech.com/show/7335/the-iphone-5s-review/3
There's nothing preventing it from being on the same die, either. The fact that it's a coprocessor just means that it's a separate processing core which the main (general purpose) processing cores must communicate with through a bus. It could even be clocked synchronously with the general purpose cores and it wouldn't matter.