There are 4 lenses you can buy for your NEX 5: the 30mm macro, 18-55, 18-200, or 16 pancake.
Why people decide to buy the Sony's over the Oly's/Panny's is beyond me. Sure the sensor is a little bigger, but there are only 4 lenses availible, and out of the 4 lenses, only 1 of them is any good. The rest are either slow, mediocre, or both.