My capacity says 29.3gb.
It's nothing new. iOS itself has to take up some space.
Mine says 13.4. Interesting. It's usually been in the 14GB range.
Yupp. The 16gb should be in the 14gb range. I think it's 14.6gb? I don't remember.
^^ Probably your best bet.
Although iOS 5 could take up more space, but it's doubtful it'd be 1gb more than iOS4.
Currently my 3GS 8GB, is at 6.8GB on Version 4.3.3, so it will be interesting to see how much more iOS5 eats up when it comes out properly.