@Tegra2 vs Exynos: The screen shot states "this enhanced version...". Is it then save to assume that a non-enhanced version will work with non-Tegra2-SoCs?
Honestly, most I've heard/read about Tegra2 concludes that it is too late, i.e. it would have been killer had it arrived when Nvidia wanted it to (last summer), but now it gets beat by pretty much every other modern dual core Cortex A9 chip out there. The fall refresh might change that again, but we won't know when those SoCs will hit phones/tablets.
As for games being Tegra2 exclusive, I personally can't see that. At the most I see it being similar to iPad and iPad 2 with the latter having higher polygon count and more bump-maps etc. But you will still be able to play them with Exynos or OMAP4xxx. And probably even single-core SoCs like Hummingbird.
Exynos manages to record 1080p30 video whereas the Tegra2 only does 1080p24, so it likely will be the more powerful chip. We won't be able to settle this debate until the retail versions arrive and have been thoroughly vetted. I have pre-ordered the Exynos version. I don't wish the Tegra2 purchasers any ill and I think both versions will be successful.