IF the remake happens....
If the planned remake actually gets made, i think the worst thing they could do is keep the makeups and "monsterish" characteristics exactly the same as they were in the original show. It was already a stretch in the 60's to see people reacting in terror to the way they looked (which is actually what the show hinges on: the interface between the Munsters and our "normal" world"). Trying to do that, with the same looks, today would be pathetic.
Im not talking about altering the characters personalities, just their physical appearance and nature. Herman should be Frankenstein's monster, but not the classic Universal studios version. Let him be what the Frankenstein monster truly is: a stitched together zombie. For Lily and Grampa, let them look like the feral vampires we know from "Lost Boys", "Buffy", etc.. Eddie should transform into a werewolf frequently (and ditch the Little Lord Fauntlaroy costume straight away).
I know what Im suggesting is sort of heretical, and believe me I LOVE the original show, but this is 2010, not the early 60's, and I think that the only way that the new version will fly will be to take that into account, otherwise we simply have another copy of "The Munsters Today".