[wetbrain]

That's certainly true, but I'd say most seasoned users on reddit don't subscribe to much of what's on default front page. The default reddits (funny, pics, f7, atheism, politics, etc) are basically as you describe. Rehashed memes and populist statements.

Anyone who's been on reddit long enough has a front page of all the sub communities they follow, and probably only a couple of the defaults.

The pop-culture types get the pop stuff and the veterans get the small, focused culture, so everyone's mostly satisfied.

When one community starts becoming watered down, someone will usually start a new subreddit, rather than go to a new site altogether.

Altogether, I think these will give reddit better longevity than slashdot/digg.