First off, suspension does not mean collapse. Effectively the democratic institutions are being ‘moth-balled’, for an indefinate period to allow for renegotiation between the main Northern Ireland parties.
All powers decentralised from the Westminster government will be taken back. Even so, the Assembly members will continue in office on shadow salaries (around two-thirds of current pay), though there will be no debates or committee meetings. In fact no official duties will be carried out at Stormont. These come under ‘Strand One’ of the Belfast Agreement (aka the Good Friday Agreement).
Out of the institutions established under Strand Three, the most likely survivors are the Policing Board and the North/South Ministerial Council. The Departments of the Executive will continue to operate along current lines. During the last suspension (which lasted four months), Peter Mandelson ran them all with just two junior ministers. However, it now seems likely at least two further junior Westminster ministers will be appointed.
Thanks to Ian at Stormont Strategy.