Just to chime in on the Guild Wars angle here . . . 1) GW expansions will be higher priced than EQ's expansions . . . 2) GW is basically a giant LDoN . . . everything is instanced, which means there will NOT be a lot of hours and hours of QA to ensure the persistant world is balanced and golden for their players. Although some of EQ's work is less than golden for sure . . . and to see EQ charging more money when more and more of their content is becoming instanced . . . well . . . um . . . at least you can still raid stuff . . . you can't do that in GW 
At this time, we don't know yet what Guild Wars expansions will cost as there have not been any released. EQ expansions have been around $30 on release. Even if GW expansions were to cost the same amount as the original game ($50), in a little over a month that fee would be met with the cost of EQ expansion (ie. $30 + $15 per month) .
As far as the mechanics of EQ versus GW, EQ is still a game based on a '98 engine. Yes, some overhall was done with the release of Shadows of Luclin (and other various patches), but not much. When GW patches a zone, they simply place the files on the server and tag the system to let the client know there is new content that needs to be downloaded and installed when the person attempts to enter said zone. This is a revolution in patching and reduces downtime considerably. The content gets more readily updated this way and there's is less downtime required since they don't have to bring the whole freakin world down to do it.
As far as raiding, yes, it does have it's moments and merits. However, I still find that the most enjoyable experiences I have in EQ is doing dungeon crawls with a group. LDoN's happen to be king in this area thus far and I'm disappointed that the same feel did not carry over in DoN as much.
One thing I have to say, as far as MMO's go, EQ still leads the way with me. This is most likely due to the fact that I have been playing EQ since September 98 and it has become a sorta nostalgia for me. I feel this is the feeling most of the old player base feels as well. However, this is also one of themain reasons why I have adamantly argued against SOE raising the monthly fees in EQ. To me (and I'm sure many others) it feels as if SOE is preying on this nostalgia in hopes of milking those of us who have built this nostalgia for the game and giving very little back. Smedly promises to implement all new character models; then they turn around and act as if he didn't say it and state that they don't foresee doing this anytime in the future. Broken issues go on unfixed. At least Bill Gates brought Microsoft to a halt for 6 months in order to address fixing holes in their software (ie. he addressed the issue which is more than I can say for SOE who has totally ignored these issues). And time and again it has been said that the whole newbie experience has to be re-worked in order to bring new players onboard with EQ. If these areas go left without attention, then I see EQ following the same slow death that Ultima Online has endured which is sad.