I live in China, and am engaged to a U.S. citizen. It is already October, and he is about to file the I-129F visa petition for me. Should I be worried that these visas will run out for the year? How long is the normal wait?
First off, there is no limit on the number of fiancé visas (category K-1) that can be approved each year. (Some visas are subject to annual numerical limits, and therefore potential waits, but the K-1 is not among them.) So the only waits you will face have to do with processing times, which vary depending on current numbers of applicants and how backed up the relevant government offices are.
After your U.S. citizen fiancé submits the Form I-129F to U.S. Citizenship and Immigration Services (USCIS), he can track its progress on the My Case Status page of the USCIS website. Average processing times for this petition tend to be around six months. Making sure the application is filled out completely and accurately the first time around, with the latest form and the proper fee, will help avoid any delays. See K-1 Fiance Visas for more guidance on this process.
Upon approval of the I-129F visa petition, your case will be transferred to a U.S. consulate in China. You will be sent additional paperwork and asked to attend an in-person interview. This part of the process usually takes several weeks at least. Once approved for the fiancé visa, you can enter the United States, after which you will need to get married and (if you wish) apply for a U.S. green card within 90 days. (If you don't apply for a green card, you will need to leave the U.S. within the 90 days that your visa lasts.)
For more information, see Fiance and Marriage Visas: A Couple’s Guide to U.S. Immigration, or consult an experienced immigration attorney.