Now that it is a really special comet, and every one is talking about it, why doesn't it get a name, instead of just a number?
In fact there is a better name for 67P, which is 67P/Churyumov–Gerasimenko. It was named after the two people who helped discover it in 1969.
Churyumov identified 67P while studying photographs of Comet 32P/Comas Solá, taken by Gerasimenko.
FYI, the official comet naming convention can be found at the IAU website. They give the comet the name based on the information they have on the discoverers. Wikipedia also has great information on naming comets.