Testing on my shaman w/ 168 hit rating (6.4%) 1% hit from racial 3%hit from talents, total 10.4% (anything over 10 should work for my puposes). I was casting on a NE Moonkin w/ the 4% resist talent and 0 nature resist.
1st set of 500 casts: 22 miss (4.4%)
2nd set: 34 miss (6.8%)
total 56miss/1,000 casts = 5.6%
Seems to me like spell hit completely fails against both talents & racials in pvp. Don't bother going past 4% spell hit.
I do have screenshots of my test results if anyone really cares. My last post(testing hit vs just the racial, no talents) I uploaded a ss to imageshack which was way too small to read and nobody seemed to care, so I didn't bother to upload anything this time.