It's going to be interesting, to say the least.
Hopefully a decade away from Dwarf has reinvigorated Doug Naylor, who after a reasonable series VII (some very good, some awful) went on to do VIII which was utterly embarrassing.
As for this Corrie - Dwarf cross-over. Well, Robert Llewellyn's Twitter page has basically said 'Don't jump to conclusions' so lets just hope that this is some Comic Relief thing, or something which doesn't feature too heavily.