> I've come across a significant minority of people who need that "www" as a clear signal that it's a website

Now more than ever. Before they opened the tld floodgates you could be pretty sure [word].[commonTld] could be put into your browser.

So yeah, guess we have to keep using those 4 letters or come up with alternative solutions. Funniest I've seen was an ad using http:// instead.