Here's a quick FAQ which should answer most of the reasoning behind the change and whats next:
Have we destroyed PvP?
No, the numbers show that.
Player Kills Player
Tuesday July 25th: 21,697
Monday July 31st: 27,661
Tuesday August 1st: 22,796 (+5% compared to previous week, -18% compared to previous day)
So yes, these changes have had an impact. And we're looking very closely at them. But we still have plenty of players dieing to other players.
The danger with looking at statistics like this is the people who were being habitually ganked while gathering are still going to be ganked while gathering regardless of what you do short of making a fully safe area for them to gather in. They are getting ganked because of bad decision making on their part. All a change does is shift what constitutes a bad decision.
Please look at how this change has effected small group conflict in the black zones. Engagements where each side only has 2-5 players.
Do not make the mistake of looking at statistics with out context so many developers do. Just looking at a target number of kills per capita or something can result in a very wide range of ways those kills are actually being generated. From a pure statistical standpoint a single massive zerg camping a zone and killing every single person that enters it would be equal to many dynamic skirmishes between different groups in that zone. Those would clearly not be the same thing from a players perspective at all, regardless of equal number of kills generated.
The dismount change can work, but its caused problems for small scale open world roaming that will need to be addressed.