Apart from posting current dates, State Department has also added special notes to Visa Bulletin mentioned above. Please see full details below:
D. SPECIAL IMMIGRANT (SI) TRANSLATOR CATEGORY VISA AVAILABILITY
Given the limited availability of visa numbers and the existing demand, the Department expects to reach the FY-2018 annual limit of 50 Special Immigrant Visas in the SI category early this year. As a result, it has been necessary to maintain a May Final Action Date of April 22, 2012. It is likely that number use will require the SI category to become "unavailable" in the coming months. Once the annual limit of 50 visas is reached, further issuances in the SI category will not be possible until October 2018, under the FY-2019 annual limit. The SQ Special Immigrant Visa category for certain Iraqi and Afghan nationals employed by or on behalf of the U.S. government in Iraq or Afghanistan is not affected and remains current.
Continued heavy applicant demand will result in the Vietnam Employment Fifth preference (EB-5) category reaching the per-country annual limit during April. As a result it has been necessary to impose a final action date on this preference for the month of May to control number use for the remainder of the fiscal year. It can be expected that the Vietnam Employment Fifth preference category will remain subject to a final action date for the foreseeable future.