For those who do support this change, the present sense of urgency is to get this into law before William and Kate's first born arrives. Their view is that if this present opportunity is missed, the "built in gender inequality" they object to remains in place for another 2 generations (another century or so).
If this were a simple matter of the UK Parliament passing a single bill, it probably would have been done by now. But as was pointed out earlier, all 16 Commonwealth Realms where the Queen reigns would have to unanimously agree to any change in succession rules, in order to maintain the status quo (well, status quo except for changing the succession). That is a slippery slope, which probably would lead to some realms ending the monarchy all-together instead of changing the succession.
I say leave it alone.