I looked into to buying this MY, and ultimately decided to wait for the LCI...
My main reasons:
2nd year of a production run... given fuel pump scare, want every opportunity for any other "kinks" to be worked out.
Adjustable side bolsters -- if my new 3 has them, the 2014 M5 better have them -- it would be even nicer if they were dynamically adjusting like in the Mercs... but we will see.
New LED headlights... from what spy photos show-- and what is already on the 3/6/7 -- the squared off lights look meaner.
new LED taillights
Side mirrors with turn indicators - again, have this in the 335 I bought last week, and like it.
New steering wheel
Ceramic controls? hope this will be allowed at least as an option.
Hoping for new trim... possibly like the CF that currently can only be purchased aftermarket
iDrive upgrade? debatable when they will debut the new touch top iDrive controller.
There also appears to be a nice, subtle bend from the headlights to the kidneys (you can see it in 6 GC, and appears to be in the spy photos).
All of these are speculative.. some firmer than others, but are why i I will wait.
I plan to try to get a july production date for ED in September i guess?