There have been some big changes to the game since 6th launched back in 2012, notably expansions like escalation and siege assault as well as the development of supplements and data slates. This has caused a lot of unnecessary distress amongst some people - are these things legit in a standard game? Can you bring this or do I need permission from my opponent? etc and so some clarification would be helpful (even though the rules are clearly stated...)
What I can see is that these clarifications for expansions will be bundled together into a new book, making it more a 6.5 than a 7. This would be a good move and might appease the community by removing any confusion, even if the answer isn't the one you wanted to hear (yes I can bring a baneblade now get over it!)
Whilst it's true I don't get many games in, I have to say that I haven't had any real issues with the way the game plays and as such I don't really see what they would need to alter to improve the system. In fact the only gripe I have is with assault vehicles - or rather the lack thereof - I'd make all vehicles assault vehicles but you roll a difficult terrain test on the disembarking charge whilst those that are specified as assault vehical wouldn't.
One rumour I've heard is about a dedicated psychic phase that works much in the same way as the magic phase does in fantasy with a variable power limit each turn etc. whilst this would work well in 40k, I think this randomness is one of the key draws of fantasy and it would detract from that system if it was implemented elsewhere.
On another note I've decided to clear out some models so I've put my Grey Knights, CSM and Dark Angels up for sale. Being realistic I'm not going to get round to them, there are too many cool things on the horizon (Wood Elves, Blood Angels and Space Wolves!) and as I don't have the codexes it seems a bit pointless. Hopefully I can funnel some of the money into new releases or possibly a new surfboard, it is nearly summer after all!