Looking over some of the forums on two popular ArcheAge fansites (http://www.aaportal.net/en and http://archeage-online.com/), you'll notice some concerns about the game's pvp penalties, goals, rewards, etc. A little extra digging and you'll notice that some long term guilds from sandbox games such as Ultima Online and Darkfall are keeping their eye on AA, but I've yet to hear of, say, World of Warcraft guilds really paying attention to it (with one obvious exception ;P ).
As a quick introduction, ArcheAge is a Korean developed game (made by one of the creators of Lineage) that is attempting to combine both sandbox and theme-park elements into the same game. For closed beta 3, testers were able to reach level 20+ in a matter of days (which the devs seem to like), build houses (both solo and with help), and build ships for naval combat.
Most of the pvp concerns are based on this beta test. AA does not have a NDA, so testers can share everything and anything about the game, and have done so. CB3 focused on the early levels of the game, and primarily on the "WoW continents;" that is, the continents controlled by dev created factions, not the pvp continent for player factions.
The game's jail system (which allows victims of same-faction ganking in friendly territory to turn in blood off their own body as "evidence" to put said ganker in prison) is being seen as a problem. Again, note that this is for same faction slaying in essentially newbie territory on the continent that does not allow pvp sieges for assets. Most sandbox players probably recall Darkfall's racial alliances, and the fact that "going red/blue" was pretty exploitable and had little consequence, scaring away most of the non-hardcores and eventually leading to an overhaul of the system. If AA is supposed to be attracting theme-park players, I would think having little reward for this sort of action, combined with high risk of being sent to prison for 30 minutes in-game time, help deter same-side ganking so that new players who aren't used to hardcore play styles can be lured... er, tricked... no, um... eased into the free-for-all pvp experience. Those who are complaining about the jail system seem to have largely forgotten about the theme-parkers in this respect, but this shows up in other areas too.
"Item loss on death;" this phrase alone sends shivers down the spine of most theme-park MMOers. Back in Asheron's Call, this wasn't an issue at all, since we collected "death items" in order to help ensure that we didn't lose our best gear. Besides, the best stuff usually was random loot, not quest/"raid" loot, and the latter very rarely took weeks on end to earn. Looking at the WoW player base, who may raid for months to obtain an item, the idea of losing items on death is enough for them to avoid even free trials of a game (I know, since I tried seducing some WoWheads to the dark side, including some AC vets who didn't want to go back to this as a death penalty). Item loss on death is largely relegated to niche pvp games, which is where many of the current AA fanbase is coming from, but is not the sole target audience. AA's current death penalty seems fairly simple, in that you simply respawn at your chosen respawn point and have a short debuff placed on you. This is a pretty laughable penalty for most sandboxers, and maybe some theme-park players. But let's recall that AA is trying to get both parties to play the same game. If the pvp continent allows us to conquer player towns, rape farms, and tax people off their land, we're going to have to make something lenient to entice the theme-parkers into giving AA a chance. If the pvp continent also has the best resource and mob locations and long runs to said locations, death becomes meaningful again. As someone who had to repeat 20minute+ runs in Darkfall when I tried to run naked to my guild's new location, alone through enemy territory, I can tell you that time lost can be a fairly brutal experience. When you tell a WoWhead that you celebrated the end of a 2-hour journey, they freak out ;P
Finally, I find that analysis of low level pvp tends to mean little in the long run. The concerns about pvp prior to the level cap seem near meaningless, since games rarely tune their game for this until it becomes a huge problem. The jail system helps mitigate some problems, such as high level traitors faction-ganking their own side, and that's probably the limit of what should be dev controlled in order to satisfy theme-park players and sandboxers. Same side faction is still an option, but it leads to potentially joining the third faction (pirates, who can attack or be attacked by anyone). Theme-parkers get their safety net, sandboxers have their options, all in newbie land. Concerns about rewarding pvp with items, such as in WoW or Rift with pvp currencies, are too hard to judge without seeing end-game content. After all, the only current "battle ground" is essentially a recreation of the end-game siege system on a very small, instanced scale. The training aspect leads me to wonder if the rewards are, essentially, for training purposes as well, meaning that end-game may not have many rewards beyond what sandboxers are used to: the thrill of the kill, the removal of an enemy, and potentially the acquisition of new land or an other player's gold (via house taxation).
In all, AA seems to be going to great length to balance between sandboxers and theme-parkers, but because the sandbox crowd is usually relegated to niche games, they are forgetting the other half of AA's target audience. Theme-park players are notoriously thin-skinned and willing to drop games quickly, with many frequently seeing pvp at detrimental to their experience. The idea of limitless possibilities without directed content and dev policing is what keeps the masses from experiencing games like EVE and Darkfall. AA is essentially aiming at "sandbox-lite," and should be approached as such. Those expecting a new Ultima Online will be sorely disappointed. However, those of us with softcore friends may be rewarded with a game that will finally seduce our carebear counter-parts into trying a game with more player-created end game content, so that sandboxers can bring their friends to sieges and while still allowing them to hit the hamster wheel... er, raid content, all in the same game.