Some developers don't make money from making some open source projects - but they can always use it to showcase their portfolio to get hired to some company.
Android Bitcoin Wallet is earning money from donations.
Blockchain info recieved about 30.5 M funding to invest in growth - they are building a brand and maybe that can offer some consultancy to other bitcoin startups.
Xapo - they are making money from fees on bitcoin to debit card conversion.
Coinkite sells bitcoin cards and terminals and make money from withdrawals from merchant accounts.
https://getyikes.co/ - another bitcoin web wallet works as bank - money deposited on account will generate revenue for customer and part of this revenue will go to operator. (disclaimer: i am founder of this service)
