Ann: NHC: Revised Offer for Macarthur Coal , page-9

It's about preventing a yes vote on Monday at this stage. Bidders don't want to be the first to show their hand. Xtrata's feeler was rejected by the large shareholders, otherwise the first you would here about it would be an announcement and change of substantial holding, like in 2008. Value is still higher than price atm so unless you're a short term trader you should relax about the corporate action.