I don't think startups or small companies should be looking specifically for "Android developers", or "X developers" for any language or platform value of X. Instead, they should be looking for generalist developers who can learn whatever platform they need to work on.
They should, but look at most job ads. Then again, I had an initial interview with a guy the other day. I re-read the job description, and I wasn't strong in many of the technologies listed, though I have a very generalist CV, so it seemed to appeal to him. The thing is, I am often put off allying for jobs like that.
