"it is regrettable" refers to people in general. "It is regrettable (for us all) that..." "I am sorry" = It is regrettable for me (but not necessarily anyone else, though that might be true.)

No it does not mean the same thing. The first sentence is a general observation that expresses the situation as not good. The second is a personal statement ( as opposed to a general one) that expresses personal regret. John

They do not mean the same thing in conversation, but literally 'sorry' indicates regret, therefore they do literally mean the same thing, although 'it is regrettable that~' usually indicates that you regret somebody else's decision.