I know that people cannot say publicly, but if there is an Impression 4 (or whatever the next update is after 3) alpha or beta out there, I'd love to help test it. And if there is a Mac version floating anywhere, I'd ESPECIALLY be interested! Please private email me info and I'd love to help out!
Disclaimer: Although I have spoken of Mac version, this no way indicates that there is any version or ever will be any versions. Just a hopeful plea.
Thanks, Rick coauthor Mastering Civil 3D 2012 I blog at http://simplycivil3d.wordpress.com