It is pretty annoying how little hit there is on the new gear, but I haven't found it to be a serious impediment to my tanking yet. That said, I do keep a few older pieces of hit gear in my bags for fights I think I might need it.
What are you tanking specifically that you feel the need to gem hit? My guild is working on ToC hardmodes, and I don't feel like I have any room to gem for anything but stam for things like Gormok on heroic ToC25. I actually had to talk to our rogues about giving me tricks instead of spamming each other with it :(