Deus Ex: Human Revolution Interview

Rather than simply be content with the new gameplay trailer, screenshots, and Q&A released by Eidos Montreal earlier today, Eurogamer has taken it upon themselves to quiz Deus Ex: Human Revolution game director Jean-Francois Dugas about the augmentations, weaponry, and character advancement options we were shown in the trailer. Some good clarifications packed in here:
Eurogamer: What are Praxis Points and how do they work?

Jean-Francois Dugas: You earn Experience Points for every mission you complete, every secret you discover, and various other meaningful actions you take. By collecting experience points you will unlock Praxis points - something you need in order to acquire and unlock new augmentation abilities.

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Eurogamer: How does stealth (cloaking) work, exactly? I assume it doesn't last forever, or does it?

Jean-Francois Dugas: It uses energy. We have what we call "passive" and "active" augmentations. All "active" augmentations use energy. When depleted, you can't use it any more. So, you need to find/buy nutrients to recharge your energy cells to use your augmentations again.