The first pricing for the F10 M5 is in - for the UK. The 2012 M5 will be priced at £73,040 for UK buyers. At current conversion rates, this is approximately $118,306 US Dollars. Keep in mind however that the new M5 will be priced lower in the US. To give you a basis of comparison - the 2008 E60 M5 cost £65,890 in the UK, while costing $82,900 for the US.
Of course currency rates were different in 2008 than now, but using the same UK-US price ratio difference (~25%) from the 2008 model, the 2012 M5 would cost $91,895 in the US.