This accession is remarkable in two ways. First, it clearly signals an increased interest in the Apostille Convention in the Middle East. In this regard, it should be noted that the Apostille Convention entered into force for Bahrain on 31 December 2013 and for Oman on 30 January 2012. For a list of Contracting Parties, click here.
Secondly, it will greatly facilitate the ease with which public documents circulate in this region (and globally) as in some of these countries a legalization, especially for commercial documents, is either very expensive or the fees are dependent on a percentage of the total amount of the invoice or a tabular fee. See for an example here. The price of an Apostille should be, after all, reasonable.