It's entertaining, but I think it simply says more about our current ultra-mediated time than about President Obama. Politicians of all stripes get into trouble when they go "off prompter." In an age of YouTube, Twitter, 24-hour cable news, the Daily Show, the Colbert Report,etc., a tiny gaffe or awkwardly-phrased comment can become a big issue. When a figure is as visible, powerful, and under as much scrutiny as the president, it's probably better to risk being made fun of for using the teleprompter too much than to risk saying something stupid off-the-cuff.
And speaking from manuscript is nothing new, though the teleprompter technology is fairly new. Indeed, since George Washington, presidents have been using prepared manuscripts for public speaking. There are really fascinating archived speech manuscripts from Lincoln's presidency in his handwriting with commentary from several other advisers.
Ronald Reagan was excellent delivering scripted speeches in a way that seemed off-the-cuff; his training as an actor helped. If you're interested, Peggy Noonan's What I Saw at the Revolution details a lot of the preparation that went into Reagan's speeches.