Xenforo has a "Spam" button at the bottom of every post.

In IPB we have to go every time to ACP to ban some spammer which honestly is a hassle.

XenForo button has pretty much same options as IPB options in ACP.

Are there any plans for including something like that in upcoming IPB 4.0 version?

For now I'm not aware of any IPB hook which can do that.

You can do this already by visiting a users profile and clicking "Flag as spammer"

To configure what happens when a member is flagged for spamming, go to System Settings > Members > Spam Prevention in your ACP.

You can set it to automatically ban a member and delete all of their posts in a single click.

Unless I've misunderstood what you mean, hover your mouse over the user name on the left of their post.

A popup box should show, and one of its options is to Flag as Spammer. We use that here.

Aha, something I didn't know.

Thanks guys :)