It should for a couple of hours (let's face it, if you're gonna show it off you're gonna keep the screen on at all times, pressing and clicking and activating features and using them left and right... while in normal use 50% should even get you through a work day, it doesn't when you'll be pushing the phone to do everything
) In any case, remember that the best practice is to let your battery charge to 100%, let it discharge COMPLETELY until the phone shuts off on its own, and then re-charge to 100%. (NOTE: This is not to improve the battery, it actually doesn't give a rat's behind whether you charge it half-way or use 10%'s all the time, but the software needs to calibrate to accurately show your battery percentage)