With Mendes losing Deakins and - if I remember correctly - Newman, a new approach might be just what the doctor ordered to keep this from being too much like SKYFALL.
Mendes could certainly do worse than sticking to "Tinker, tailor..." and not only hiring its cinematographer but also its composer, Alberto Iglesias. His score for "Tinker, tailor..." was excellent.
Keeping Newman wouldn't make it being too much like Skyfall, in fact, it would give Newman the ability to further explore sounds and themes in the next film. I haven't read or found anything on the net about Newman leaving or returning, but seeing how Newman won a BAFTA and Grammy (If I recall) not mention other numerous awards for scoring Skyfall, I'd be shocked if Newman wasn't called back by Mendes and EON. If Newman doesn't return, then I'd be certainly fine with Alberto Iglesias scoring, though I'd personally go for Daniel Pemberton. His first big break was scoring Ridley Scott's The Counselor, and it sits as one of my favorite scores of 2013. I'd honestly would like anyone other than David Arnold. I don't think Arnold's style of Bond Scores fits Daniel Craig's era. Sounds too much like Brosnan's era (duh, obviously)
Maybe I remember it wrong - but I do recall one bit of news/rumor/whatever quoting Newman as unwilling to do another Bond.
Which would be a shame - I love his SKYFALL score. If he can be persuaded to return - yes, please!