It would be cool to have SSL Intergration, so if you have an SSL certificate on your website you can allow people to login using that, and view Administrative Areas as well as their User Control Panel through it too.
Don't think there is much needs to be handle just once SSL is on you can change the forum url to the secured one or specify which sections should be considered secure and viewed through a secured page.
Actually i am not sure about IPB, I personally did not see such setting in the ACP i must say. But yea the concept is that you'll force users to view certain pages IE: Login Page through a secured connection.
I'm hoping site wide SSL is available simply by specifying it on the base forum URL.
More and more folks are accessing via mobile devices these days, it makes sense to at least encrypt username/password details when logging in, but also useful to encrypt all site url's and associated web traffic.
I already have certs, and I have had a few hackers from my previous forums that were able to capture login credentials. So now I rather stick to https for all login processes. I have hired a small CentOS security team to secure my sever as best as possible from attacks.