This seems to be everyone's first concern when looking for Chinese literature, but allow us to (very humbly) posit that what you want isn't actually the youngest, hippest new authors in China. It is true, first of all, that there are vast quantities of new writing by younger writers getting published in China every year. By far the most vibrant aspect of literary culture is the writing being produced on literary websites, now bleeding into traditional publishing. Unbelievable quantities of new writing is coming out of these venues, and the best-known writers are received as pop stars.
However! The books these writers produce are aimed solely at a readership of urban, under-25 (realistically, under-20) Chinese youth, or upwardly mobile young professionals, and as such are almost guaranteed not to appeal to a general Western readership. They almost all belong to highly-circumscribed genre categories that are particular to China — school romance, historical fiction, martial arts fantasy, etc. — and are written as disposable reading material, to be consumed in quantity and discarded. Trust us, we have read large amounts of this stuff, and translated more than we would have chosen to. You will hear the names Guo Jingming, Han Han, and Zhang Yueran – and increasingly categories like "post-80s" and "post-90s" (as well as the newer back-formation "post-70s"). When you do, we encourage you to assume there is precious little of interest there, and move on.
This is not to say that these writers produce nothing of value, or that, of the enormous amount of content being produced online, there won't be some cream that floats to the top. Only that youth writing is not the gold mine that it might appear to be, and skepticism is recommended.
Most of the "youth writing" that has been translated into English (such as Beijing Doll, or even Shanghai Baby) does not belong to this trend of online or genre literature — within China those books are considered non-mainstream, even controversial, and have relatively small readerships. Whatever hip young authors emerge in the future, they are likely to do so in a similar fashion: within a subculture of rabid fans, but ignored or shunned by mainstream culture.