First off. I recall Jon Peters saying this most recent livestream that they want to make less differences between skills in PvE and PvP. I think this is actually the reason that PvE (including WvW) is so imbalanced right now.
Since I know the devs are logic based people I want to use this post to examine the pros and cons. Please feel free to add your own in the responses.
Side Note: You will notice that WvW and PvP can be considered vastly similar in the way that they play and PvP balance applying to WvW would actually solve many of the current balance problems in WvW.
Pros:
Objectives are different, ergo the skills impact play differently:
In PvP the objective is to score more points than the other team. This is done on most maps by capping and bunking points. The combat style is close quartered and you are solely concerned with keeping the other team from scoring more points. So skills that deal damage in an aoe ring (mark of blood necro balance) have more affect than they might in a wvw/pve situation where you do not need to stay in a small ring in order to accomplish an objective.
In PvE the objective is (usually) to kill mobs in order to get to a certain place/kill an end boss. The mechanics of the bosses are very variant, and so are the obstacles that you have to overcome in order to get to where you need to go. Because of this variance, skills that are solely geared around capping and holding points/killing other players that are more intelligent than AI are going to function in odd ways in this environment. If a skill is highly powered in PvP it may be near useless in PvE or vice versa. For example Healing signet in PvE is over powered because of the slow attack speed of mobs and the limited use of poison by mobs vs PvP where players attack rapidly and know to poison you if you are using HS.
In WvW the objective is to have a final score that is larger than your opponents at the end of the week. This is accomplished through holding capture objectives at 15 minute intervals, stomping other players, and killing sentries. The map space for this is quite large so fights can often take place in very large quartered areas. Mobility plays a big part in combat (the ability to escape reset health, let cds expire etc.). The fights can also range in size from a 1v1 situation to 50v50. So in a situation like this a skills related to mobility (teleports, stealth, etc), can be far more powerful than they are in PvP where stealth is not nearly as useful of a mechanic as it negates capture point contribution.
Phoenix Ascendant [ASH] | Rank 80