ob-clojure.el should use separate cider functions for value and output
results, in order to avoid expressing standard output as some kind of
programming-language string with embedded \n notation.  I experimentally
adjusted my copy of ob-clojure (obtained from git clone -b master today)
like this:

(1) In the cider block, access the result-params.
(2) Put either 'cider-get-value or 'cider-get-raw-value into a variable,
depending on the result-params.
(3) funcall the variable instead of using cider-get-raw-value directly.
(0) Up at the top, add a declare-function for cider-get-value, next to the
declare-function for cider-get-raw-value.

(defun org-babel-execute:clojure (body params)
  "Execute a block of Clojure code with Babel."
  (let ((expanded (org-babel-expand-body:clojure body params))
    result)
    (case org-babel-clojure-backend
      (cider
       (require 'cider)
       (let* ((result-params (cdr (assoc :result-params params)))
              (cider-call-fn (cond ((member "output" result-params)
'cider-get-value)
                                   ((member "value" result-params)
'cider-get-raw-value)
                                   (t 'cider-get-raw-value))))
         (setq result
               (or (funcall cider-call-fn [...]

Together with :wrap example as suggested by Thomas S. Dye, the results are
exemplary.