Well Castlevania has always been a Konami game, so having it done by another guy at Konami really doesn't change much. The same people are in the loop and it doesn't look like gameplay has changed much; it just has a different lead director. Games change directors all the time... Just look at Soulcalibur. The director for 3 and 4 had completely different visions than the director for 1 and 2.
Metroid The Other M is a different story however. That is a Nintendo game, going to people who have never had anything to do with Nintendo, changing the gameplay radically; essentially making it a completely different game that has nothing to do with the other Metriods, except for the fact that it has Samus Aran and Metroids in it.