Fans know for definite that the Cybermen feature in this particular episode or the subsequent second part, “The Big Bang”, as they have been featured in the series trailer. However there is also the possibility that original classic series cybermen might also return and not just those created by Cybus industries.
There are also strong suggestions that the Daleks may reappear once more and these would be the re-designed Daleks that were created during “Victory of the Daleks”. There is also the possibility that the Sontarans may return too. Essentially any enemy caged within the Pandorica could be released and this might lead to the production team creating new foes or utilising existing ones.