Throwable weapons were underwhelming in Morrowind. So were crossbows. I wouldn't be particularly excited to see either in DLC.
Bows were also underwhelming in Morrowind. One time I shot about thirty arrows directly at enemies, and much less than half of them actually inflicted any damage, and I don't think the damage was even that great. Of course part of what made the Marksman skill so useless in Morrowind was the dice roll that was calculated on how high your skill was for using different weapon types, which just so happened to make it aggravating to even bother with ranged weapons. Come to think of it, bows were pretty useless in Oblivion without mods. Firstly in Oblivion, they had the crosshairs on the screen that did not actually represent the actual trajectory at all, forcing you to continually guess and miss, and then on top of that, it would practically take about twenty to fifty arrows to take out an enemy. The last part isn't always necessarily true, but there's definitely times in Oblivion where it feels that way.
Skyrim's bows are not perfect, but they have definitely been improved if I'm actually using them to (at least help) take out some of the deadlier enemies in the game from a distance as opposed to previous games where I would either forget I have them or avoid them like the plague. If they could do crossbows for Skyrim and make them worthwhile (by that I mean that they actually
do damage to enemies), then I'm all for it. Spears and flails would be pretty cool as well. Those weapon types would add some variety to the game, which is never a bad thing so long as it's done right.