Oh, wow, there's really going to be a third Deus Ex. I don't know how I feel about that. Well, actually I know exactly how I feel about it: at first I was completely wary but then this teaser made me giggle like a little girl (one part of it specifically.)
I'm coming back round to wary though. It's being developed by Eidos's new Montreal studio, which means, probably, no Warren Spector, no Harvey Smith. Eidos probably doesn't even know everyone who'll be working on this yet. Sheldon Pacotti might. I would love it if they brought back Chris Todd (who wrote all the unvoiced text -- datacubes, books, etc -- in the first game.) What are those guys doing these days anyway.
If this was a Deus Ex "reboot", or even if largely ignored the story of the last two games I'd be happy. It's hard to make a good Deus Ex game, it's impossible to make a good Deus Ex game that follows this convoluted continuity. Let's see something (mostly) new.
And how often have story-heavy franchises switched creative teams and not screwed it up? I'd say Knights of the Old Republic II and Curse of Monkey Island. Even Curse has a caveat since, while it was quality, it wasn't quite in sync with the previous two games. LucasArts pushed their luck by bringing in another creative team for the next Monkey Island game. Whoops.
I'm going to give Eidos the benefit of the doubt for now, though I probably shouldn't. I would love for this to be good.