The consensus seems to be that you have to have been here for several months and have 100 quality Hubs before anything other than pennies are rolling in. You also have to be very active, to build a base of readers and links. If you worked at it every day for two years, you might have a decent part-time job.
No one actually lives off of their Hubpages income, but it's a great place to start and gain experience for online writing. When considering all of the shared revenue sites, Hubpages is one of the best. There are a few people, with several hundred, or even thousand Hubs, who are making some serious money. However, that will take years to achieve.
If you are going to write anyway, why not get paid? Seriously though, don't quite your day job yet.