I thought it was a cover when I heard the song in the commercial. I don't think they deliberately copied Such Great Heights. Read about cryptomnesia on Wikipedia. Melodies get reused here and there. It can be deliberate, but here it doesn't sound like they heard Postal Service's song and decided to swipe it. More like they wrote it and it ended up being the same melody. It's a pretty simple melody to begin with.
個人意見: 首歌幾好聽! 美中不足的只係 "由Alan作曲" e句 改番做 "Composed by Ben Gibbard and Jimmy Tamborello" (quote from wiki)就好了 =) 咁心入民心既chorus部分俾人抄左, 同samsung抄apple個rectangular with round edge design, end-of-image bounce-back, tap to zoom touch-screen function, etc 有咩分別 XD