you need at least 3 evidence to be qualified for EB1 or EB-2 NIW, that is listed in your I-140 instruction. For years these requirements did not change from 1997-2003 through the INS public cases. But the evidence itself has been denatured. there are so many special requirements added for the evidences like membership, papers, news media. The INS think paper publication is a postdoc's job. Your paper is not considered as your evidence unless it was published in PNAS, Nature or Science. they only know these tree journals with intnational impact based of their high school diplomat. So you may only qualify for one or two of the evidences by references letters.
at least you need a patent, a national award, reported by national newspaper or professioanl journal like your paper is featured, cover etc. otherwise you'd better wait untill you find a permanent job.
Again, I will say paper itself is not very persuasive, but the featured paper should be counted into 2 evidences. evidence of your original, scientific contribution to the academic field and the evidence of published material in professional publications, written by others, about your work in the academic field. Plus your references letters (evidence of recognition by peers), you should at least have 3 evidences and meet the minimum qualification. The success may depend how to organize your supporting documents and make your petition letter more sexy. When I have time, I will summarize my experiences and post online if it is welcome. I like many GREers in China, they contribute so many in TOEFL and GRE forum.
You will know I am telling the truth if you had read the INS denied cases. If you read more than 20 cases, you will certainly know the requirements for an petition and how to prepare your evidences and all the supporting documents. I just got my NIW approved by DIY. Papers is not as important as you expected, if say by weight, it only ~10% for postdoc, 15-20% for other titles. You need different evidences to support your petition. In theory, once you have Advanced degree, you may be able to apply NIW. But in practice, you also need at least 3 evidences to prove yourself having extraordinary ability that you can accomplish the project of Nationa Interest. The weight of this ability may be much less than EB1 case but still needed. Unfortunately, I talked to many lawyers, they did not read that all the open denied cases (maybe they do not know CIS has a webpages showing all these open cases, even they do not know the NIW is requiring an waiver job offer, not a labor certificate. You may ask lawyer to prove what I said here. I would trust myself at least I know what I have submitted to CIS. That is my successful expearence. I saved some of the cases in my local disk, if anyone need, please leave your email.