I think her success as a freighter is essentially confirmed. 18 orders at launch and SQ is widely expected to order 16 very shortly. This is just the tip of the iceberg, and hundreds of frames should be a solid probability.

As for the 747-8I, she is still in the running with QF. QF needs to eventually replace her 743s and 744s and the 773ER was not part of the last RFP (which went all to the 787). This implies QF wants her replacements to be 350+ seats, and that means 748I or A388. And I do not believe the A388 can replace the 743/744 on a one-to-one basis. So that improves the chances of the 748I, since the 773ER was not considered in the original RFP and the A346HGW is now pretty much not an option.

BA is still up in the air. SQ has a lot of 744s to replace, but if she adds to her existing 773ER order, that implies she has chosen to downgauge for the most part. She still has 10 A388s on option, as well, to handle selective upgauging.

CX is a huge 744 operator, but some believe that with all her peers flying A388s, she must, as well. Maybe. Maybe not. Or perhaps a small A388 order for the highest-density routes and 748Is for everywhere else.

Of the domestics, I think NW is the most logical choice, since she operates nothing in the 777-sized market and has chosen the 787 over the A350, so she will continue to not do so. She has 744s and 742s she will eventually need to replace. Either she downgauges fiercely (A330/787) or she upgauges slightly with 748Is.

I believe UA's future is the 773ER and 772LR, but will admit the 748I is a possibility. The trick will be if UA can increase frequency intra-Asia and to Australia. If she can, I see 773ERs. If she cannot, I see 748Is.