You won't have a problem. I renewed my passport at home while holding on to the old one that had my current visa. Re-entered China using both. My danwei than simply got the current visa re-issued into my new passport.

Was impressed that this time around various government agencies, PSB, banks were completely non-plussed at reassigning a new passport number to my file. Was a bit of a headache last time I renewed back in the mid-Oughts.