I have read many posts in this thread, although not all, I see many interesting points, some of which could actually be implemented. I was once a PvE only player, after about 4 months of playing, I gradually migrated myself into PvP, my first HA experience? horrible, made me want to quit.
But I stuck with it, grinded myself out of rank 0-2 hell, took me almost 3 months, but i did it, through listening carefully and actually taking the time to learn, I made many high ranked friends, some of whom today are quite famous in HA.
Today, after about 6 months from which I first stepped into HA, i am now rank 9, if i have to label myself as either PvP or PvE i would have to go with PvP, but I don't see why many people thinks that PvP people do not play PvE.
Some one complained about the elitism in PvP, I will attempt to explain it rationally from a PvP player's standpoint - when PvE players first go into PvE, they are unwilling to learn, thus getting defeated, but once they learn something, or defeats someone, many tend to get big headed. They will thus go into HA saying rank does not matter, I am as good as any rank 6,9,12 player when that simply isnt the case. And when the more experienced PvP players sees this sort of reaction, bursts of frustration will be expressed, as to the degree of the language, well that vaires with said PvP player's temper.
An example would be: The first ever Mending Warrior goes into PvP, someone tells them, Mending is not good, the warrior does not listen and brag about being the last one alive on the team, the other people on their team develop stereotypes : Mending wammos=noobs. Then come the 2nd Mending warrior into PvP, patience starts to run out and flaming begins, you get the point... I was there, back when I was rank 2 I would blame everyone for not letting me in their rank 6 team when the problem was myself, that my skills simply wasn't good enough, I realize this looking back now, I probably will look back on my experience now 2 months later and laugh. It is all part of the learning process.
People that complain about rank are one of two things, they are either hypocrites or they are stupid. For instance, if rank does not matter, then why would rank 0 players complain about not getting into rank 9 groups? Because all the other rank 0 players are horrible and they think they alone in the rank 0 crowd stand out? Wrong. And if rank DID matter, then why not simply play with people of your own rank, earn your way to higher ranked groups like everyone else that plays PvP.
From my personal experience, TRULY good PvE players tend to be fast learners in PvP, they may lack the experience of a high ranked player, but anyone that is truly good at a game understands the mechanics of the game and will adapt quickly in another aspect.
In conclusion, to address the question presented by the OP, How can PvP be made attractive to PvE players? Nothing, if a PvE player wants something more out of this game, aka being recognized when they enter an arena, or have people know who they are as well as knowing that they are one of the best players in the game, then said PvE player will pick up PvP. Those that give up aren't meant for PvP, for the learning curve in PvP, high end PvP anyways, is VERY steep. Those that will have paid their dues, learn the builds, better themselves of instinct, knowledge, experience and reflex will one day be known and respected in the PvP community as well.
Hopefully my post is not too contraversial and start a flame fest.