Do we know for sure if it's the first two episodes that will be aired, or merely the first two to be filmed? We know that they frequently film stuff out of sequence to actual airdate. In the case of Matt Smith, they first filmed "The Time of Angels" and "Flesh and Stone" before doing "The Eleventh Hour"; Peter Davison and company did "Four to Doomsday" to get the ball rolling before filming "Castrovalva"; and for what it's worth "The Christmas Invasion" was in the can before David and Billie did that post-regeneration scene for Children in Need, though that was more of an afterthought I believe. Point being, while I'm sure this guy knows his stuff, he seems more of a movie guy than a TV director and so for a premiere story I'd think the Moff would want an experienced director to handle it - unless they're looking for a different look and feel again, which is something the show has been doing of late.
Still, I hope that it *is* a two-parter and not a case of this director filming two separate episodes, which again is something they do in filming blocks. We ALL miss Doctor Who two-parters, and if it is the premiere, establishing a new guy across more than one episode will be a switch, since the previous three guys all had one-shots to get going. Lots of options here!