Are you Saying that Obsidian Needs to Layers Instead of One. And that It is now Breakable?
If So that's a Bit Worrying.
And Another thing. To patch up the hole where the wire and redstone etc come out you just turn the wire in another direction immediately then you have a Obsidian Block 1 Block away from the hole. So if there is a Meltdown/Explosion then it Would still be contained.
This is what I mean.