As things stand it appears I have four options with regard to Skylake as this is the definite architecture I want to upgrade to next.
1) Buy i7-6700K platform this year and sell some of my 775 stuff to recoup some of the cost.
2) Buy Skylake-E when it releases, sell the Z170 but keep DDR4 ram
3) Have two separate desktops; one with i7 6700K and the other one housing Skylake-E. (i7 6700K desktop can perhaps go to one of my family member)
4) Wait it out until Skylake-E and then sell some of my 775 stuff.
Too many choices
Yeh I'm thinking something similar - I'll probably go with 32GB DDR4 (4x8GB) for my 6700K/Z170 setup, just so I have 4 dimms ready for Skylake-E quadchannel memory. I don't fancy getting 4GB dimms at this point in time, too dated.
I'll expect that 32GB kit to last me 5-6 years minimum, making it good value for money.
The only issue could be if Intel make Skylake-E have hex-channel ddr4, not sure how likely this is - I saw the new xeons will use it, and Skylake-E is derived from Xeons, so who knows