Lesbians and feminists are already preparing the champagne to celebrate the day when men are no longer necessary to make babies.
More seriously, a couple of years ago, a lab also managed to fertalize a female mouse with cells from the egg of another female mouse, so it seems that there are several promising ways to create artificial sperm cells from females. It's certain that it will become possible to impregnate women with artificial sperm cells in the near future.
And it's true that male fertility has been dropping regularly for many decades now (possibly centuries, records just don't go very far back), sperm counts are getting lower and lower with every generation, so it's not like the real stuff may be around forever. A 100% female society may be the future of mankind.