If they did away with hit/expertise then I would miss gemming/enchanting/reforging, however, because of these bloody stupid stats, every time we get an upgrade we end up having to completely re-do the entire reforge to make sure we aren't above/below the hit cap.
Enchanting is less of an issue because there aren't many options for each slot, and one being clearly BiS (usually) but with multiple gemming options it has the same problem, just less so, as reforging.
So send hit/expertise along the way of the "defense cap" and keep the system as it is (imo).
-edit-
And to those who say "it's easy", it isn't when you min/max (which fortunately I don't bother anymore since I don't raid). When you min/max you often end up reforging a stat off one piece to reforge the same stat back on another. This is because you want to get as close to hit/expertise caps as possible without wasting any points going over. Thus you might take 300 hit off one piece, to put 250 back on another because you were 50 over the cap. This is why so spreadsheets/calculators are virtually mandatory for leading edge raiders. Yes, you can eyeball it and get it "pretty close" but not 100% perfect every time.