Blessing of Kings has a short post on PvP up, and summarises that he likes the idea of PvP, but not the inherent level balance thats created in a purely PvP server. As a tank I rarely PvP, I don't have the burst damage to kill things, my survivability is limited vs casters, and none of my aggro abilities work, in short, PvP for tanks just doesn't work. However PvPing is fun occasionally, and I think Blizzard are right to include a contested area in WoTLK, but it should go further, and be more restricted. Being in Horde territory should flag me as PvP, within my level range, that is being in a contested or enemy are should be a bad thing even on a PvE server, the factions aren't friendly and aren't likely to look on your presence with a smile.
Allowing level 70s to simply go and gank lower levels doesn't feel like a good thing, it seems more like a level 70 should just ignore low level enemies the same way critters and enemies won't attack us when we pass by. Being in an enemy area and getting attacked by someone in your level range or below seems good, its realistic, the person is a threat, a viable target, an evil
There are a lot of people that do go flagged, often with a hidden rogue to ambush you (though I like the rogue part, I can kill those :P), and it makes sense, its a loud abrasive offensive enemy trying to make you be the antagonist, the factions are under a truce, it doesn't mean we are friendly. I think this opens up the possibility of a real world changing plan, you have your factions core areas, and cities, these are yours barring server events where something huge may happen. Then there are the contested zones, big warzones where pvp is flagged and valuable resources are (so herbs, minerals, random elementals), there are also areas that change control based on how long you can hold it, if a server can hold an area for a week they get a nice small town with some daily quests (and the opponents get a mounting "offensive" bonus), 2 weeks a few towns and with a month of being held a keep and support, but you can always lose it. Make PvP part of the game, make objectives and real changes in the world to make people take part to participate, its not always that PvP is bad, just so much more fun if there is a reason and sense behind it rather than just farming honour for a new toy.