That must be what they mean by "non-literal copying":
- Semantic XHTML
- SEO
- Facebook Connections and Like Buttons
- Style Variables
- Content Specific Search
- Inline video, or video embedding
- Improved CMS
- Following a user
The issue with "non-literal copying" is somewhat complicated. I started to write a thread on this point but gave up because of the complexities...I figured that people would not catch this point, but, actually, I think it is a very important issue- one that vB will lose on.
For some background, read this:
http://digitalcommons.lmu.edu/llr/vol21/iss1/6/
One of the important issues that I think is missing in IB/vB's argument is that they own the copyright to the structure and sequence of the code in the first place. (Remember, the plaintiff has the burden to prove each element). Past that, though, I think there are substantial failings in separating idea and expression in the claims in the first place. I think it is a huge deal that IB has abandoned literal infringement and has shifted to "non-literal" copying as the basis for its claims. (I think they have made their case harder to prove, but have injected more technical legal issues into the case by doing so).
In looking at the tests applied by the courts, it boils down to a two step analysis on "intrinsic" and "extrinsic" copying and each have different tests as well as issues on whether expert opinion is allowed to support the point.
Overall, complicated legal issues; to sum up my opinion, though, it still resolves in XF's favor. This on two bases- first, I don't think IB can show it owns copyright to the structure and sequence of the code. Second, I don't think they can show the expression of the code is similar enough to warrant a finding of infringement.