Intel turned personal in their battle against NVIDIA's Ion earlier this week, with the release of a "Competitive Position Guide" that systematically attempted to undermine the HD-capable netbook graphics chipset. Now NVIDIA have struck back with their own document, somewhat obviously titled "NVIDIA response to Intel claims on Ion", in which they address each of Intel's criticisms.
Like Intel, NVIDIA use feedback from various websites to illustrate their points. It would be interesting to hear whether the company approached any of the sites used for prior permission; Intel has been criticized for not doing that when putting together their document, as well as taking quotes out of context.
In summary, though, NVIDIA's points are that while Intel may not have validated Ion, Microsoft and OEMs certainly have, and that while Intel claim the chipset will be outdated come Pineview, the next-gen Intel platform will actually force users into Intel graphics with only minor improvements over current-generation technology. You can read some of the key slides in the gallery below; for the full NVIDIA document, as well as Intel's original critique, check out netbooknews.it.