Did some testing late last night with Urist on the duel server it appears:
Arrows are currently only cut damage, it took me the same amount of arrows for Masterwork Bodkin as it did with normal arrows (Both +3 damage). That'll get changed soon so technically nothing has changed for archery other than the fact that the best arrows have become expensive versions of the worst temporarily!
Secondly, from what I can gather, the horse bump - bump rider thing isn't supposed to be quite so effective and all this whining about "omg i'm going to need to respec!?!" is very very premature since WSE has only just been added and things are still needed to be tested regardless of whether or not they've been tested previously, give the devs a break, they're doing their best to make sure that the game works in the correct way.
As far as I understand it, they're going to stop the rider bump for different speed cavalry, I don't know whether or not they wanted it to work under a certain speed or above one (both would make sense, fast moving cav would lean into their swings and would be trying to kill you while going slower would reduce the effects of a bump anyway but you wouldn't be on guard quite so much so you'd get caught out.) but just hold your horses, pun intended, and wait for things to get ironed out.
I have no news on anything else since we only tested those two things, not even sure if I am allowed to post this but I am just to give the devs some time to do their job. It's always like this after a patch and this is no exception due to a technically massive update and change to the equipment the devs have to work with.
Some details on the archery testing:
Masterwork Longbow
Masterwork Bodkins/Arrows
6 Power Draw
159 Archery
Plate armour body shots with Bodkins: 4/5/5/6 arrows needed
Plate armour body shots with Arrows: 4/5/5 arrows needed
Medium armour body shots (Kuyak I believe) with Bodkins: 3/4/4 arrows needed
Medium armour body shots (Kuyak I believe) with Arrows: 3/4/4 arrows needed
I'm not sure on the type of heirloomed armour, if any nor am I aware of the ironflesh differences between the characters (strength too) but comparing the number of shots that it takes to down the enemy just by the different types of arrows it was suggesting that the "arrows determine the damage type" wasn't working as planned.
Pre-patch I would consistantly down a heirloomed Kuyak in 3 shots and a plate armour wearer with 4 (5 if str & inf build) so I could clearly see a difference with the damage.