Learned so far

In a short amount of time, i have been able to get up to speed very quickly with developing Android Apps.  Gotta hand it to the folks at Google, first with App Engine (develop server side applications using Servlets) and now with the Android being Java-based, they certainly do cater to the millions of folks who know Java.
Anyways I've probably spent 50 hours total (installing Android, getting things configured, looking over examples, and developing) And here's a bulleted list of things I've done and am now comfortable working on/with in Android:

The Basics

• Activities
• Intents
• ADT (eclipse plugin for Android)
• Layout Managers
• Integrating Resources (using R.)

Integrating with Platform/Tools

• Using Temporary Storage
• Integrating HTTP (Posting Data from the Phone to a Web Location)
• Multithreading (spawning and running threads)
• Integrating with the Camera
• Integrating TTS (Text To Speech)
• Querying and using users Contact Information (Querying Phones information)
• Using SQLLite (Database)
• Integrating Sounds (Button Clicks)

• Drawing Api
• Dynamic UI (showing and hiding view elements)
• Sprite integration and manipulation
• Image Manipulation (handling different Image formats, scaling/resizing images)
• NinePatch (using Draw-9 tool)
• ImageButtons (buttons that change when focus, selected, etc.)
• Page Transitions (Fade, Slide)

Not bad considering it's been only about 2 weeks of casually looking at it... I have lots more to learn, but so far, the platform and tools (ADT, Emulator, Draw-9, SqlLite)  have been excellent