I recently noticed the song Need U (Duke Demont ft. A.M.E) sounds exactly the same as Thinking About You (Calvin Harris, Ayar)

The production and the vocals sound almost identical; and the lyrics are similar, shows how generic music has got.

Take a look for yourself

http://www.youtube.com/watch?v=ISBz1S8F8N8 - THINKING ABOUT YOU (from about 31 secs in)

http://www.youtube.com/watch?v=CgTB1ay_nnA - NEED U (from about 40 secs in)

The vocals do not sound alike.
The lyrics are cheesy love lyrics so of course those are somewhat similar

Electronic music has a long history of sounds being similar so I don't understand what is shocking.

They're not alike at all. The only similarity is that they're both house songs.