I've been a Slashdot member since 1998, demonstrated by my "desirable" 4-digit UID. Papers here have been linked from Slashdot several times*, and I've submitted several stories that have been posted. I've had excellent karma for time eternal, and garner Score: 5 posts at least several times a week (it isn't exactly hard, and takes just a few minutes in an interesting story posting something of marginal interest). I try to add meaningful, well-thought out and grammatically correct comments, and I never "karma whore" (karma whoring is where someone posts with the sole intent of gaining karma, for instance posting an obvious question for further info relating to some part of the article. They don't actually bother researching it, because that would hurt their chances at getting first post, and they have no interest in the answer anyways, but nonetheless that recipe almost always yields Score: 5 (Interesting)).
 
One of the motivations for participating in Slashdot's community, quite honestly, was the quid pro quo PageRank goodness, courtesy of items like a link on your username, or a signature line (the sig is particularly spammy and is generally used for people to link to lame contests or affiliate links, but the linked username is just good form). Everytime I earned a Score: 5, it would go in the archives, autoexpanded, and would get picked up by Google, where my link would give me some ranking goodness in return. It was, in a sense, a marginal form of payment for my contribution to Slashdot. The user moderation system ensured that spam comments would never get expanded in the archives, and thus it shouldn't (depending on how Slashdot served up pages for Google) earn spammers any rewards.

I'm not sure when, but sometime over the past year (I presume), Slashdot switched to adding nofollow on all user outgoing links, so basically even Score: 5 posts yield no benefits outside of nebulous Slashdot karma. This is especially odd because Slashdot is the one site where I have almost never seen comment spam (outside of GNAA/Goatse type stuff). It seems like a pretty irrelevant thing, but suddenly my marginal interest in being involved with the Slashdot community has declined to zero. Ultimately I am selfish (like most humans), and I like to feel like there is some sort of reward for my efforts. If I'm expending efforts for someone else's benefit, I like to think that I'm earning namespace (which isn't really the case when you post on many disparate online sites, with no common user identity), or some other sort of reward. PageRank was a pretty cheap reward.

Will Slashdot die because I don't contribute? Probably not. But in my heart of hearts Slashdot is dead.

*- The oft feared "Slashdot Effect" isn't even remotely as intense as many people imagine. Basically the only reason some sites fall over is because they're 100% dynamic, generating everything on the fly from databases, going through transformations, etc. These sites often can't serve even a dozen users over a couple second period without falling over. This site, yafla.com, is almost entirely static (just as I chose my blogging software based upon it being static), and where it is dynamic it uses intelligent caching. Even on a low-end shared server this can easily facilitate a Slashdot influx.