Ah, I'm not sure about comparing EVE to a facebook game, but I do understand both the love and hate directed at it. It's very much a niche title. I played it for one summer and while I enjoyed my time with it that was enough for me.
As for Star Citizen, there will be two single player campaigns: one fifty mission long military campaign that gets you citizenship in the persistent universe should you choose to join, and a sixteen mission long campaign "in the style of The Secret Missions" which was an add-on campaign for the original Wing Commander. On top of that is the persistent universe which you can play on CIG's servers in an MMO type environment, start your own server and host as many of your friends as your rigs can handle, or play offline by yourself. Unlike other MMOs where the economy is largely driven by players, making it difficult if not impossible to play alone, the ability of the AI mentioned above, both in economics and PvE, means it should be completely possible to go it alone and still have a good time, à la Freelancer. Plus, the team plans to make weekly or biweekly(I hate that backwards word, in this case it almost certainly means once every two weeks, but it could mean twice a week, technically speaking) updates free of charge. Add to that tactical FPS style ship boarding action and you've got one interesting game concept.
Even more exciting is their plans to utilize a mod approval process to incorporate the best of the community's work into the actual universe, while still allowing all the Bronies and whoever else to do whatever the hell they like to their own private games. Given the massive and lavish attention the community is directing towards Chris' project now, I have high hopes that it will meet or even exceed Bethesda's fanbase. Seriously, for sixty dollars that seems like a ridiculous amount of content to spend hundreds of hours on. Provided it doesn't suck, of course. Thankfully, the chance of that seems to shrink with every update.
Seriously, go check out their new site and judge for yourself. Nothing like a little original research to liven up your day, and we could always use more citizens. The prospect of this being the first community funded AAA game has potential written all over it. Chris still has backers lined up to take up the increasingly shrinking slack, but having just the creators and the fans getting a say in the creation and direction of the project can only be a good thing. There are still over 50,000 Alpha and Beta slots open and there is more info being dropped every day so you hardly have to make a snap decision. Give it a shot!
Here's a vid of one of the insanely detailed ships(1.3 million polys!) to get you curious.
http://www.youtube.com/watch?v=76UF2gnLKho