Wow, I purchased the i5, and my wife has the same.. Well there seems to be a problem going across the keys when downloading from the app store. These lines go right across the top and flicker across, this has happend to my wifes phone as well. There seems to be a bug in ios 6. I hope apple fixes these problems, I've seen the vids on youtube and WOW! What is apple doing lol.
As with an software update there are bound to be bug. Apple has always been pretty good about issuing updates to address these bugs so I'm not too concerned. Honestly, it could be a lot worse...Antenna Gate anyone?
OMG I love how people get so nervous over the smallest glitch. I've been using iOS for 3 years now and can say that I've never had problems that would make me go frantic. The stuff in the news is about the underachieving maps app compared to the old google maps app. It's not the best nor the worst thing in the world though. Don't worry too much though, I assure you apple will fix the lines in the app store app.