I wouldn't worry too much. It took what, twenty three years from Action Comics #1 to "Flash of Two Worlds," then twenty four to Crisis on Infinite Earths, then nine years to Zero Hour, then eleven years to Infinite Crisis, then about five to Flashpoint? If the pattern holds true DCnU should get totally revamped by a Green Lantern crossover event around 2017. And then the rate of reboots will speed up again and put the mainstream DC universe in competition with the Legion for which gets retconned more often.