No jurisdiction now remains uncommitted to tax information exchange, according to the most recent OECD update on cross border information exchange to counter tax fraud.
Following a G20 meeting in April of this year, the OECD has published and periodically updated a list of countries surveyed in accordance with the international standard for exchange of tax information.
The Report lists all countries that have been surveyed by the OECD Global Forum in implementing the internationally agreed tax standard. Both Ireland and the UK were identified from the outset as jurisdictions that have "substantially implemented the internationally agreed tax standard". Several jurisdictions, while committed, have not yet substantially implemented information exchange. These include territories which the OECD describes as tax havens. Information exchange agreements between these jurisdictions and others number eight or nine for the likes of Antigua, Gibraltar and Liechtenstein, but none at all for others.
The current updated list is available here