Will this code change persist through upgrades?

To remove the author byline and post date in my WP 3.0 install using twentyten theme, I’ve commented out all the code for the function twetyten_posted_on() in the functions.php file as highlighted below. It works nicely.

Will this be overwritten when I upgrade? If so, what should I do in order for it to persist across upgrades? Thanks in advance.

function twentyten_posted_on() {
/*	printf( __( '<span class="%1$s">Posted on</span> %2$s <span class="meta-sep">by</span> %3$s', 'twentyten' ),
		'meta-prep meta-prep-author',
		sprintf( '<a href="%1$s" title="%2$s" rel="bookmark"><span class="entry-date">%3$s</span></a>',
			get_permalink(),
			esc_attr( get_the_time() ),
			get_the_date()
		),
		sprintf( '<span class="author vcard"><a class="url fn n" href="%1$s" title="%2$s">%3$s</a></span>',
			get_author_posts_url( get_the_author_meta( 'ID' ) ),
			sprintf( esc_attr__( 'View all posts by %s', 'twentyten' ), get_the_author() ),
			get_the_author()
		)
	); */
}