You don't need Android for that (thank god).
That does exist. Samsung used to make android interchangeable lens cameras, and now Yongnuo does.
It was awesome for its time, I could make pictures at a party, upload them to Picassa right away, and share them with a friend. It had a GPS receiver (a thing that cameras STIL!!!!! lack) so I had automatic geotagging.
I tried to get YN455, but they don't sell them in the US and apparently it doesn't even have proper English localization. I do speak some Mandarin, but I still want something localized.
But also, manufacturers could do apps and support APIs without adding a whole Android OS with all the downsides that it entails.
But maybe we're talking about different kind of cameras.
That's why it's _still_ easier to just pop the SD-card and copy files. So even Apple had to add the SD slot back to Mac Books.