With the i.MX 8 scheduled to become available sometime during Q1 of 2018,
I believe you got something wrong there. While certain i.MX 8 SKUs may be available as early as Q1 2018 certainly not yet the i.MX8QuadMax SKU we are targeting.
what are Toradex’ plans to support its dual PCI Express interfaces?
One lane as per Apalis standard and another one optionally on the SuperSpeed pins of the USBO1 port.
Is there a new carrier board in the making?
No, definitely not. It is fully compatible to our existing Apalis carrier boards being the Apalis Evaluation Board (potentially eventually with its own iMX8 type specific Mezzanine daughter card) and Ixora (albeit one PCIe lane only.
Will it be a ‘reference design’ to extend the module in a manner beyond what is offered by the average carrier?
I don’t think any such will be required.