While there are plans, they're focussing on spam management via inline moderation, so that is done, and done well, and focussing on the core functions of the software, before adding more to it (from what I understood). There's no additional spam management at this point, but I do not know up to what point there IS in the back-end. I am not aware of Akismet already being in the system.
Oh i hope they do add it then. Its a lifesaver for many forums which otherwise are quickly destroyed by spammers. This is especially true for niche sites where you don't have active staff all day. Akismet does a good job of stopping or preventing obvious spam posts.
Oh, I forgot about captcha, they use that.
I am sure when the xf is more stable, it can get extended with third party things like twitter integration or akismet support or all those sorts of suggestions.
I think it's great if Akismet makes it in, and a no limit stopforumspam key.
As long as it is in the site terms and conditions and is displayed publicly it is perfectly legal to track and share IP addresses... As has also been mentioned IP addresses are not considered personal information as every user broadcasts their IP on every single connection to the web.