PJ Williams at the Evangelical Textual Criticism blog was the first to note it; word came to him via Michael Holmes.

Bruce M. Metzger has passed.

Textual criticism is a strange field. It takes years—decades, even—to be comfortable with the variety of languages, witnesses, manuscripts, not to mention the paleography. Metzger had decades of information filed away in his head, along with recall of resources. It seems textual criticism is one field where the elder statesmen who retain critical faculties along the way become more valuable to the field, not less valuable.

He will be impossible to replace and sorely missed.

I couldn't locate a formal bibliography of his works (well, at least not quickly). Here, however, is his author page on LibraryThing. Take a look. The list is only books, so articles, monographs, fetschriften essays, conference papers and whatnot are not included, but the ground he covered is amazing.