I hope both because RDM helped push Chelsea into a more offensive team and Chelsea have bought fairly well(Torres aside) in the past few years that the team won't regress back into a Mourinho defensive boredom watch.
It would take a while to do that anyway, but I think Mourinho got very close to being fired at Real for not being offensive enough and altered his tactics significantly(and made the team better) in the second season. Considering Roman wasn't very happy about how defensive they were and his time at Real, I think Mourinho won't be trying to make such a painfully defensive team this time around.... prays.