I noticed from various Warhammer Online bloggers and friends playing WAR that very few people seem to have reached level 40 in that game yet, even less PvP rank 80. Personally I never got further than level 20, but already at that point the leveling speed had slowed down to a crawl. It appears that it is much faster to level up a WoW character to 80 than a WAR character to 40.
But when I thought about why that would be so, I noticed that of course in World of Warcraft "level 80" is not really a hard cap to your character development. Yes, gameplay changes at that point, but by doing raids and gathering gear your character keeps getting stronger. And if somebody already has the very best possible armor he can get from Naxxramas-25 and the other raid dungeons, he'll be able to further grow more powerful as soon as Blizzard patches in Ulduar.
In Warhammer Online, there is a lot less character power growth through gear after the level cap. If you reach level 40 and PvP rank 80, and buy all the gear you have access to from that, that is more or less it. Which makes sense, because for a PvP game you *want* to have a hard cap, at which all players are equal in power.
Of course Mythic could have designed the game in a way that you reach the level cap much earlier, giving everyone the opportunity to do PvP at equal footing. But they know how motivating making your character more powerful is. It isn't proven that RvR alone is motivating enough to keep players subscribing. So instead they devised a system in which people could play PvP in spite of level differences, and keep on gaining PvE and PvP ranks for a much longer time. Good idea, but it only postpones the inevitable: At some point in time the majority of players will be level capped, and the cap is harder than that of WoW. I wonder what will happen then.
Note that adding raid dungeons and gear progression afterwards to a PvP game doesn't work, and it was Mythic themselves with the Dark Age of Camelot expansion Trials of Atlantis who proved it doesn't work. Mark Jacobs has been very explicit in expressing that he wouldn't do that again. I get the impression that Mythic plans to expand the game horizontally, by adding more classes, and ultimately new race combos. I doubt we will see an expansion raising the level cap. But Mythic's marketing has been sending out hints that soon the slayer and choppa classes would be added to Warhammer Online. It will be interesting to see how in the long term a game with horizontal expansions fares against the vertical expansion model of World of Warcraft. And personally I think that WoW could use a bit more horizontal expansion instead of just adding new raid dungeons and 10 more levels at the top.