ipfw is still there, as well as a new application firewall. It looks like Firewall Builder is a GUI front end that can be used for ipfw - I don't know how much enhancing it does.
WaterRoof2 is a free GUI for ipfw that also allows traffic shaping and will do a nice log analysis for you. I tried it but did not like the fact that you cannot include comments in the rule sets, nor will it translate ports (so 80 is shown as 80 not http) If you want to use ipfw (I continue to use it rather than the new application fw - how security-conscious is the default "allow everything"?) and don't want to set rules with a text editor it is worth a look.