Don't listen to pessimism and don't give up so easily!
You've made this thread on May 25th and no one had a single suggestion for 5 days straight and probably never would. As soon as I recommended Regnum, someone's immediately trying to discourage you and recommends Guild Wars instead, a commercial game (no monthly fees but you have to pay for the original and each expansion), which is neither free nor is natively supported on Linux. Might as well recommend WoW instead. GW doesn't even consider itself to be an MMORPG. You did request "Online? Free? Roleplay oriented? Nice graphics? For Linux?" and "Scenic?", didn't you? My suggestion is the only one that meets most, if not all, the criteria, even if such criteria is only preferred and not required (otherwise, why bother mentioning it?). The point is that such thing exists and it's called Regnum Online!
In fact, Regnum is said to be the closest free Linux MMORPG to Guild Wars in gameplay. Even its webpage has similarities to the GW webpage. Not only is it a competitor to other free Linux MMORPGs but also to Guild Wars in some ways. Google for its reviews - most people place it as the best free Linux MMORPG out there at this point, so the reaction to my suggestion on this forum isn't really surprising. And while the game is a grind, it's still less of a grind than any other free Linux MMORPG and is a much more complete and frequently updated product. Check the
The Linux Game Tome for extensive player reviews on Regnum. Majority place it on top of free Linux MMORPGs.
If you're willing to pay for an MMORPG and run it through Wine, then there are better commercial games than Guild Wars with better customization and less grind. WoW's success alone speaks for itself. LOTRO is very popular as well. Just because Guild Wars may have less of a grind than some free games, don't be fooled into thinking that it has no grind at all. It has a grind like any other "MMO". In fact, it doesn't even consider itself as an MMORPG because majority of things are instanced (it's how it claims to have "less grind" than some games). That also means you won't be seeing as many people around when exploring and questing as in other MMORPGs (didn't you say you got "lonely"?).

Make no mistake, I'm not trying to convince you to play Regnum and nothing else. You're the one who asked for advice. I don't run Linux as a primary OS and I don't care what you play, especially if money comes into picture. I've only posted a suggestion and this reply because of the ongoing discussion so far.
Having said that, I'll be playing something else entirely, something that is still in closed beta at this point but is nearing its release.

PS Yes, I'm aware of "elderscrollsonline.com", which, by the way, is only registered until 2009 so far. It doesn't mean anything at this point. There MAY be an MMORPG in the works, which is great but it may be a long wait and it isn't there now.