I have been playing Guild Wars and having a blast with it so far. I finally got bored of WoW and all of the raiding end game. Oh well, maybe the expansin will fix some of the issues.
Basic core game doesn't change one bit, and you're still going to be raiding to get the 'uber' content (just with 24 other people instead of 39) come the expansion. Not gonna happen.
Guild Wars was a lot of fun for awhile but eventually I found that I couldn't complete the content unless I was grouped with others. The hirelings just didn't cut it. World of Warcraft is great in that it gives me freedom to group or not to group and I can still do lots of interesting things.
Oddly enough, that's my big issue with Guild Wars as well (and why I loved WoW as a 'casual player') - I could solo or I could group. If I didn't want to spend much time playing, I could solo without issues in WoW. Your hirelings in GW just aren't smart enough to do their thing if you want to solo there.