I've been asked this a few times and usuall yanswer the same way every time. It's really up to Narrator's discretion. If a heroic/magical blade was renowned for its unbreakable nature (like Durendal from the Song of Roland), then the Narrator may rule it will not be affected by Blade Shattering (perhaps a permanent counterspelling effect?).
Former Decipher RPG Net Rep
"Doug, at the keyboard, his fingers bleeding" (with thanks to Moriarti)
In D&D3E, Abyssal is not the language of evil vacuum cleaners.