Jimmer is probably never going to be an NBA starter. It's just not physically possible. He doesn't have the ball-handling ability and court vision to run the point guard position for the Kings. Isaiah Thomas has proven to be superior in every which way in that regard. And there's no way he's getting the start over Marcus Thornton at the two, who is almost better at everything Jimmer is good and bad at.
However, as a backup combo guard? This is probably where he belongs, and where he'll be most utilized for the rest of his career. And he's proven he can thrive in this role.
He showed sparks of that future in two matchups against the Los Angeles Lakers and Los Angeles Clippers. Fredette found a player that was probably more physically talented but had a more limited role (like a spot shooter), allowing him to conserve his energy. Sometimes it worked, sometimes it didn't (lots of wide-open threes tended to occur). However, on offense, Jimmer proved he could put points up, and at one point fueled a strong Kings second-quarter comeback that had the Sacramento bench racing to its feet.
The Jimmer Show (via kingsflix)
Of course, when the starters reentered the game (particularly when Chris Paul went one-on-one), Fredette's limitations were immediately met, and he had to be removed from the game quickly to avoid being torture chambered. Still, when you look at Jimmer, you see a smaller version of J.J. Redick--a dedicated spot shooter in college who is probably more offensively talented but definitely defensively challenged. With time and development, he can possibly fit into a similar role and be an attribute rather than a last-ditch option.