There's nothing unexpected about that.
Dell are somewhat like Asus in that they produce mobos (proprietary form factor), but only as part of a fully integrated solution like Apple products.
They go the full hog with the case, and bundle the OS/software bundle too, aswell as provide tech support to their customers.
You could say that Dell and other OEMs like them (Acer, MSI etc) are the Apple's of the non Windows PC world.
Albeit I believe that most of Dell's sales are from businesses and education rather than consumers.
Given the possibility of Cortex X5 onward being very competitive with Oryon though, I wouldn't be surprised if their initial partnership with QC shifts to a custom chip of their own merely using QC modems* - this is an option that was not previously open to them in the x86 world, and I can only imagine that they are salivating over it.
*assuming the customer wants cell modems that is, if they don't there is no reason to stick with QC at all, as plenty others do wifi and bluetooth, which gives lots of options for SKUs to suit all needs.