Ryan just posted the current development version of the wordpress site importer to github:
https://github.com/concrete5/wordpress_site_importer

When this is ready for showtime it'll be a free add-on.
This was originally written by ScottC, then GregJoyce picked it up at concrete5.  It's status is described in the README in the code, but it basically works, even with really large imports, but it's formatting is a bit rough and the data that's imported is not complete.

If anyone has energy to put into it it'd be much appreciated.

Versions of concrete5 feature rudimentary anti-spam tools, including an IP ban-list and captcha support, but no unified settings page for managing these items. Furthermore, there is no support for any captcha besides the SecureImage library, which is a bit long in the tooth (and somewhat ineffective), nor is there any support for a third party anti-spam service like Typepad Anti-Spam or Akismet. We would like to change this in concrete5 5.5.

While concrete5 can support multiple authentication methods, and has built-in support for OpenID (in addition to the core concrete5 authentication method), there’s no framework for building these authentication methods, making their settings available to administrators in the dashboard, grouping them on a login page or managing which authentication methods are available or how they are displayed. The Authentication Framework will change that.

Folks have been able to run sites with multiple languages by hand since the get-go, but these new changes will make it far easier to run a multi-lingual site in the future.