Although the info we have currently for archer reveals no melee weapon, I believe the focuse should be specifically leveling range weapons. I mean whats the point of being an archer if your not concentrating on skillin up a bow. Don't get me wrong, having a dagger or an axe can be useful for close-combat, but from what I've seen, there's no need for close combat when archers are predominately in the back shooting. As far as solo'ing is concern, I've seen a video of a Lalafell Archer pummel the crap out of some mobs with just his bow. Take it as you may, strong empasis on range weapon with little or no emphasis on melee, and as mention above from a previous post, switching your weapon will change your job,so.. long post short, Bow and Arrow all the way.
Until they release guns for Musketeer! ^^
Limsa Lominsa's storyline has a heavy emphasis on gun-usage, and there are already many models of guns / animations created, plus the Roegaydn using it in the first CS. Plus some shops with guns behind the stalls (but don't sell them yet). So I can gaurantee you Musketeer will exist, probably not soon after release since all the groundwork is already in place.
Anyway, I've been soloing on archer and not having a melee weapon doesn't really matter, point-blank shots don't seem to be any weaker, and if they are, it's not enough to really cripple you.