Unfortunately, these are just mockups. But this is what Android apps should look like these days. It’s possible for an app to look and feel like a true Android app (versus an iPhone port or cobbled together hodge podge) and still be iconic and branded. The Android design guidelines are a starting point, not a cage.
That said, I think we have a winner on the Twitter front. After weeks of bouncing between Seesmic and Boid, and waiting impatiently for a public release of Carbon, longtime Android Twitter client Plume has come out with a shiny new Holo-styled update that looks and works great. It actually looks remarkably like the Twitter mockup in the link above.