What does GW have compared to WoW?

I have recently tried WoW and I loved it, but then last night I got news about this game Guild Wars, and I was wondering whats the difference between them?
As far as I have seen GW is more PvP than WoW.

Will there be servers for roleplay in GW.
Is roleplay even possible in GW or is it just a "diablo"-clone? (hack'n'slash)
If roleplay is supported, will there be houses for players to buy and guilds to settle in?
Will there be enemy castles to raid, and siege engines to use?
I really want to try the beta, real quick in fact, as I've allready preordered european WoW and want to know if I should cansel the order for this instead, so where should I look for a beta-key?

Thanks for any help

(PS: I really love the way that arrows fired from bows goes in an arch to the target, unlike WoW where they go in a straight line.. Its small things like this that makes me enyoy a game better)

EDIT:
I just some answers to my own questions..
GW is not an MMORP, its more like diablo but with muchmuchmuch better graphic and muchmuchmuch more players
Would be wrong to compare GW with WoW.

But my questions about the ability to roleplay still stays

[Chupin]

Roleplay ability will be there in guildwars, just slightly different than what people are used to. I see much oppertunity for a guild to roleplay, but the roleplay would have to be combat oriented, as the nature of the game leans toward pvp.

Currently guilds get a "guild hall" that they can customize with npc's, but there isn't any player housing in the world that can be purchased.

Currently there are no siege engines.

You can pre-order GW at multiple stores, usually for 5 or below, and play the first weekend of every month until release.

To compare WoW and GW I'll do it bluntly, WoW is far superior in the PvE, fighting mobs/dungeon crawling department. WoW has an elaborate quest system that is very refreshing, and the world is absolutly gigantic.

GW is more focused on PvP and player conflict. The PVP in GW blows WoW out of the water.

[Valus]

Completely different games. First off, I don;t REALLY believe that wow is supposed to be pvp first then pve, I think its the other way around, and Guildwars is PVP based. You're gonna find great competition in guildwars and have it be skill based competition, rather then a game like wow where skills are involved but the Zerg has a lot to do with it. more differences: Wow is gonna be somewhat time based sink. GW wont kill your schedule and consume you, and in that way it's great. Ummm I will try to think of more, does this answer your question?

[bezerkerz]

When you said GW is not a mmorpg well ur wrong it is....