If you wait for the 70D, why not wait for the 7DMkII, or the 5DMkIV, or the megapixel monster? You can enjoy
the wait agonizing over specs, resale value, lack of color choice, debating DXO marks - or you can go buy a
new lens and keep on shooting. All the xxD models have a pretty good depreciation record and you should be able to extrapolate from there if you're that interested.