Allmost everything is possible *on theory*.. In practical level, Pegasos has multiple adwantages over those you mentioned..
1) Pegasos 2 hardweare is well tested and available hardware.
2) Genesi/Freesale has active developer seeding program..
3) Pegasos has OpenFirmware.. this lessens port work cause it's allmost identical to PPC macs..
