Recently Businessweek announced that Android had passed iPhone for market share - 27% -vs- 23%. But when I pointed this out on Tech Republic one of their bloggers noted that this is a little misleading because the Android market is so fragmented - different phones have different features (e.g., Bluetooth support) so you can't just develop an app and deploy it to 27% of the market - some apps might use features not available on some phones.
I'm a newbie at Android development so my question is: Is there a CORE set of Android features that I can target so I can write Android apps that will run the same on all current Android phones? That is, to call itself an Android phone or Droid phone, or whatever, is there a minimum feature set which must be supported? If so, where can I see the list?
If no, then how can I guess what percentage of the Android phone market is capable of running some app I write?
If this is a dumb question, just remember, I'm a noob. Thanks in advance.