Honest opinion on boyfriend bringing up having kids talk/?

two weeks ago I brought up with my boyfriend the fact that I want to get married and I would prefer not to wait 3-4 years to do it. Of course, first reaction was " hmm I have not really thought about marriage yet" (justified, we have been dating for less than 6 months). What confused me was the fact that yestrday he asked me while out having lunch, " how would you call a baby boy? and a girl?" and we started exchanging names for a good half an hour. Then we agreed on two names. However I am confused now, as he is in school for the next two years and we have not talked about marriage yet, nor he has proposed. Do you think he is making a step towards committment, or what is happening here? PS> he is a very honest, straightforward guy.