No matter what, if Rondo gives us absolutely nothing else, he served 2 purposes. 1) He's still better than Pangos, and he's keeping Pangos off the floor thereby preventing any number of Cavs fans from going postal, and 2) He got Valentine off the roster.
Now he serves as a stopgap who can allow Goodwin to rest instead of Goodwin playing 48 minutes, or resorting to the dreaded Pangos. Beyond that any other positives in terms of veteran leadership, mentorship and schooling up guys like DG and Sexton and Goodwin, that's all gravy.