"Dark" sites (private, not searchable by bots) vs public sites
Subscription-only sites vs freely available sites
Related to above: the "logged-in" web vs what you see without a login (first pages, etc)
Facebook vs non-Facebook (one-stop shopping vs free range grazing)
Universally readable websites vs content viewable only on certain types of browser, e.g. "not viewable in Internet Explorer"
"Fast lane" transmission for crappy TV shows vs everybody else (coming soon to a non-neutral environment near you)
Dialup vs broadband (speed determines content)
Mobile web vs deskbound web
Apple web vs non-Apple web*
Scammers/spammers/crooks vs the innocent
*Update: Was asked on twitter "What does this even mean?" Answer: censored apps and onerous licensing on "sexy" hardware vs non-users of that hardware
Update 2: Some Apple users assume Windows users have the same unquestioning brand loyalty as they do. My twitter interlocutor used the phrase "your beloved Windows"--hilarious. This person actually reads my blog. The same person accused me of fanboy trolling as a linkbait strategy--like I need Apple zealots reading me. And played the age card - nasty. That suggested a new Balkan category: "old ppl web" vs "falling into manholes while texting" web. And finally, this person noted logical fallacies in the above writing, prompting a reminder that the post is called "sketch of the balkanized web," not "logical, non-contentious categories for easy assimilation."