One of the things I like about not having block quoting is that people tend to be far more careful about what they quote. It keeps the discussion focused while also being visually pleasant.
So, "Yay!" blockquotes, but a bitter-sweet "yay" and one that includes a, "Can it be done better?"
I don't find it visually pleasant at all when I get confused about what's quoted and what's not, and when everyone is forced to come up with their own quoting scheme since it's not supported. Some use double quotes, some use italics, some use double-quoted italics...
It's a mess. I'd much prefer a consistent representation for blockquotes for ease of reading and semantics. It's the Right Thing.
Actually, constructively, opt-in blockquotes might be interesting: you have to click to expand what was quoted making it clear if someone is quoting too heavily.
