I would likely say yes, it will use uboot. All ARM based devices use uboot as far as I know. If its compatible with pandoras autoboot.txt depends on how the firmware will "look" like. But for what purpose should it be compatible? I don't think you can run the pandora OS on pyra neither (too pandora specified). Maybe if someone wants to mod/hack it or whatever there could be a chance to. We'll see
I think more intresting would it be to know if ED plans to support the "new" GPT parition tables on pyra? I know well there is no real need to as far the MBR is enough, but it would be a nice feature for a mobile device. Only thing I imagine now is to have a compatible eSATA harddrive from which we could boot (since we have eSATA ^^).
Theoretically the GPT support should already work out of the box on debian, but for booting we need the support in the firmaware (correct me if im wrong)...