Here's most of the comment I posted in his LJ about it. Context is available at the BG blog post.
When someone else writes a fix-up, it's an "episodic novel." When I write a fix-up, it's a "mosaic novel." I think the sequel to Blood of Ambrose should be a mosaic novel, too.
If I were pulling all my Star Smasher stories into a book-length collection, I'd order the first four chronologically, while breaking up the fifth existential one as interludes, basically glueing the pieces together with high-minded, ham-handed literary tricks, making the final act a climax of the mind (The Space King that Star Smasher has been searching for all this time is actually... himself!)
If you think about it, any book with more than four POVs is something of a fix-up mosaic novel, since each character's story would come out around novelette length. If each of those stories take place is disparate times or locations, the book fits even more neatly into those definitions.
Damn, I'm a wordy bastard.
What do you think about mosaic novels? Do you hate them? Love them? Or does it depend on the book and author?