Actually as I understand it the A350XWB - which is a significantly different beast from the A350 as originally proposed - has an all-new systems layout and design, largely derived from that which went into the A380. The training ethos for the A350XWB also has a greater emphasis on hand-flying than the Airbus FBW types that have come before. Also, based on what I've read you are correct in your assertion that the A350XWB is a slightly more conservative design when it comes to reliance on electrical systems - this has been a rare case where a US design has been something of an R&D guinea pig as opposed to its European counterpart - see also Airbus's reversion to NiMH batteries for certain applications while the issues with Li-Ion designs are ironed out.
You can get a pretty decent overview of the relationship between the A350XWB and B787 from the relevant Wikipedia pages for both types - in fact the larger A350s are designed to compete with the proposed B777X.
While researching the recent JAL orders for the A350XWB, I came across this quite interesting article outlining the relationship between the types - though obviously it is restricted to how those differences apply within JAL's business model:
http://airchive.com/blog/2013/10/07/...-airbus-order/