Naturally - but there are extremes and it's still the very beginning. There are definitely people earning very little (arguably EVERYONE is earning very little - even the top people are receiving just over minimum wage in the U.S.). Up until now there hasn't been a tool to have this consistent weekly donation for Open Source contributors. But given the growth that we're seeing on Gittip I hope that we can get to the point where people are seriously considering quitting their jobs to work on Open Source full time. It's doubtful that this will affect me now -- but I would've killed to have had this back in like 2004-2006.
The old reality (people giving money to Open Source projects /developers sporadically) was bad. The new reality (consistently giving small amounts of money via Gittip) is better. The future (large amounts of money, equivalent to a paid job, in a consistent manner) will be even better. I'm pushing Gittip because I see it as the best way to bring that future about. It'll take a lot of work but it needs to happen - for the benefit of all Open Source developers.