I would always prefer to do:
"There is no greater joy in life than typing a sentence, realising it needs a clarification, a caveat, an addendum (in the same sentence, not a new one) and, guess what, parentheses are right there for you."
The parentheses bind tightly to "an addendum" and change the meaning
> There is no greater joy in life than typing a sentence and realising it needs a clarification, a caveat, an addendum (in the same sentence, not a new one) and guess what? Parentheses are right there for you.
That's what I'd do. Note the conversion of the first comma to "and," as well.