The upgrade from Vue 6 Infinite is $395 to Vue 7 Infinite and $99 to Vue 7 Complete. It's an awesome product but because I've been having so much stability issues with it I'm not gonna upgrade.

Most interesting new features seem to be:

• Ecosystems 3, the ability to do unlimited ecosystems and to paint them on any surface
• More realistic spectral clouds
• New plant system and more plants included
• Faster radiosity rendering
• New water editor, allowing easier creation of stormy water and such

Here's a presentation video they made for it:

http://www.e-onsoftware.com/products/vue/vue_7_infinite/v7i_video_layout.php