One obvious line of approach is that, if an institution is considered too important to fail, then it should be made safer and, therefore, less likely to fail. On that front, it is proposed that institutions judged to be systemically important should be subject to an additional layer of required capital.
Work on this is currently being done in both the Basel Committee and the FSB. Another line of attack (and this isn’t mutually exclusive with the first one) is to reduce the prospective impact of failure if it does occur.