Requisites have been officially released: http://www.ris.gov.tw/cs/763
From the Foreigners in Taiwan FB page:
The Department of Household registration has now added a web page that explains the process for 'high level' professionals to become dual citizens under Article 9 of the recently amended Nationality Act.
A high level foreign professional can initiate the process by contacting the appropriate central government agency window listed in the 申請推薦理由書之各中央部會主管機關聯絡窗口 (the first PDF on the page).
The contact window will explain what documents are needed to demonstrate the requisite achievements in "technological, economic, educational, cultural, art, sports, or other domains" as defined by the Standards for Defining High-Level Professionals for Naturalization announced in March.
Note that if you cannot identify the correct contact window, you can contact the Ministry of the Interior and the Ministry will ask the Executive Yuan to determine the correct agency.
After documentation has been submitted, the agency will complete an application for a recommendation of naturalization (歸化國籍之高級專業人才推薦理由書) and review the supporting documentation. If the agency approves the recommendation, it will forward the case to the review committee "organized by the Ministry of the Interior and conducted by relevant agencies and impartial individuals." If the committee approves naturalization without loss of original nationality, the foreign professional can start the naturalization process at his or her local household registration office by submitting the approved 歸化國籍之高級專業人才推薦理由書.
The new webpage explaining the process and listing the contact windows is currently available only in Chinese.