Inop,
As reported on Rumours & News thread, CX have issued an RFP for supply of up to 12 used B744s. They have also contracted with Boeing/TAECO to convert up to 12 to freighters but, until they know what used aircraft are available, they won't know whether they will convert some or all of their existing older B744s or some or all of those to be acquired. Preference is for RR-powered but if they can't secure all 12 with RRs they may switch to GE-powered if they can find them. I believe that PW power would be a last resort.