Adding page links to content that automatically convert to pretty permalinks?

Here is example of simple shortcode that will take ID as argument and echo permalink for it:

function link_from_id($atts) {

    if( isset($atts['id']) )
        return get_permalink( (int)$atts['id'] );
}

add_shortcode('link', 'link_from_id');

Usage:

[link id=1]

PS by the way non-pretty permalinks will keep working just fine if you enable pretty mode later and, if I remember right, will be redirected to canonical pretty version.