Zandaris can probably best answer the WoW comparison. I feel graphics are much better than WoW and it doesn't feel like as much of a grind.
As you level up, there will be a population increase. The 50+ players mostly seem to hang out in Inggison which is a Balaur area accessible once you hit 50. The 40+ players seem to mainly be in Reshanta (The Abyss) and Heiron.
There will be an XP boost that starts tomorrow and lasts about a month, plus some other events to celebrate 2.5 being released on the 25th. That will help get you leveled to more interesting areas of the game and you will get deeper into the storyline.
I love the PvPvE aspect of the game. The other day, Zandaris, UXZero and myself were doing a quest in Inggi when some Asmos showed up. We took off after them, along with some fellow Elyos. It was a blast!
I wish the trial was longer to give someone a true feel of the game. Poeta just doesn't do it, unfortunately.
I saw you online at level 6 a few minutes ago. I tried to invite you to the Legion but you had already logged. A few of us were on so it would have been a good opportunity to ask some questions.