Whoop got to play some WAR this weekend, first impressions . I leveled a few chars to about lvl 5 and my favorite Disciple of Kain to lvl 11.
1. Leveling,Questing and Combat is pretty much same as WoW. Questing is more streamlined [if you used QuestHelper in WoW, basically you have that in WAR].
2. Public Quests is alot of fun actually, such a simple concept. No need to make groups (although it helps) , it just happens, and sometimes it happens when you're busy doing something else and the big boss starts stomping on you :/.
3. Everyone seems to be playing Destruction. They outnumber Order on every server.. Destro = the new Alliance it seems.
4. Alot of the servers are full already [on the destro side], pick a Medium Load server or be ready to queue.
5. Scenarios aka "Battlegrounds" , so far plays pretty much like Arathi Basin , except that there's more than one map [finally] , and a few interesting "environmental" stuff thrown in. The one map, the flag-area actually explodes [killing everyone in a certain radius], so you can't camp/defend it just by standing there

.
6. RvR aka "World PvP" , i've been into 2 warzones so far. The first one was pretty much quiet and worked alot like "Plaguelands" in WoW [ where you cap the 3 towers and such]. Except Mythic did a very good job to make it all worthwhile and a few rules so it's not a stupid "Tag-team" thing. doing stuff in the warzones actually means you win the zone, and winning the zone gives all kinds of bonusses.
7. The 2nd warzone had a battlekeep, i actually ran in there to open a flightpath so it was a bit high lvl for me, but i got caught up in a siege...and wow...Order was launching a massive attack on the Destro Battlekeep and it was catapults/turrets and nuking all over the place...the battlekeep itself also got the oildrop stuff coming down on top of the order guys tryign to come in and lots of scattered pvp'ing. As a lvl 11 inbetween lvl 15-20s (yes it's not max lvl people doing this), i ran behind the lines and started chopping down some turret thing..and then something big exploded on me..ded

.
8. Social/Channels is a mess. It's very quiet in public chat, probably because people are actually playing and not farming/grinding. The chat UI can do with some work though, i've found it extremely hard to follow. Not sure why. I think the NPCs are talking too much. (yes i know you can filter it, but it doesn't seem to be saved when you log)
9. I have yet to find a "capital" or "hub", so far it's a VERY linear path from one little camp to the next as you level up. <-- i believe this adds to the reason why public chatter is ded, no one is in a specific zone for long.
10. You can do all this stuff from lvl 1 ! Scenarios seem to increase everyone's rank to an average rank, so you can actually do a scenario as a lvl 1 with lvl 10 people.
11. DYES!! If you played GuildWars you might know , how amusingly fun this concept is [and how expensive it gets]. WAR basically copied the concept [for the better] . You got that Blue Armor, you change the colour to whatever you want...or rather to whatever colour you can get. I already noticed the NPC dyer did not have Black...and dye drops from mobs too...so just like GW, black will probably be pretty valuable at some stage

.
This alones makes customization alot better than WoW, you can actually remember a player just because he had some silly bright yellow robe on.
Anyway, i was actually pretty bored initially, as it felt EXACTLY like WoW in the first few levels. Push through to lvl 10 where you get close to the battlekeep stuff. It's clear if you just want to solo PvE, you will probably get bored fairly soon. You must do the Public Quests and RvR stuff to see where things start gets interesting.