I'm still using my D200 for wildlife/nature photography. I have been close to purchasing a D300s - higher ISO, better AF, additional features - but decided to wait for this fall's lineup to see what changes. The D7K has a nicer set of specs and build quality than I expected.
I know this camera would best my D200 in most all categories, but I have some concerns regarding ergonomics. First, I'm addicted to AF-On focusing method and would sorely miss it. Can the AE-L/AF-L button reasonably perform the manual/pulse-single/hold-continuous focus capability the D200/D300 have?
Also, what is the expected diffraction limit at 16MP and what is the real penalty on landscape and macro shots? i.e. would f/16 be noticeably harmed regarding image quality?