The two methods I would personally recommend are as follows.
Firstly, sponsorships. Licensing your work to publishers brings in a lot of money, but as mentioned earlier in this thread there are not a lot of them around. However, this means there isn't a supply for the few companies that have the demand, so if you can find publishers you can get a high fee for games of fairly average quality.
Consider that this game took me 9 hours to make and has made over $3000 in license fees:
http://truevalhalla.com/mobile/hilo/
Secondly, if I were to adopt a different monetization method I would create a high-quality game in the style of Tribal Wars, or Ogame; that is, a competitive multiplayer browser-based game.
These types of games can be created much easier using HTML5, and can be distributed very easily through the same companies that pay for sponsorships (and those that rely on ad revenue.) The game would be monetized with in-app purchases or something like an optional subscription model.
I'm actually prototyping a project similar to the above. If it goes well, I'll distribute it through my network of publisher contacts and be able to reach hundreds of thousands of players overnight.
Finally, while I won't be doing this myself, other HTML5 devs find success through contract work. If you can find it, it pays very well.
Awesome article, it makes me wonder where did you sell your license fee?