[Moz]

I guess it's a side effect of the war in Gazza, in addition to Huw being on sick leave/suspended (or both).  Presumably with Clive and/or Reeta being in Israel it reduces the number of presenters available to be in the studio of the 1/6/10.  This in turn presumably limits the number of BBC News presenters, who might otherwise be considered to provide coverage for the State Opening of Parliament. 

Alternatively, they may be wishing to try out new / previously overlooked talent for such events.  It's understandable why the BBC might not want to put all their eggs in one basket again, so to speak.  Nicky Campbell certainly has plenty of experience of live TV as well as radio, having previously presented Watchdog and The Big Question on BBC One.

I presume Sophie will be doing the Festival of Rememberance?