Presently, I am on United Airlines heading to Newark for my first leg of my journey to drink Brussels. I've elicited chuckles using the phrase "drink Brussels" but that is precisely what I intend to do--almost exclusively: this is an unabashed beer trip.
Here's what I hope to hit in the next week: Bosteels, Oud Beersel, the Lambic Discovery Center, Het Anker, Cantillion and Boon. Ending in Lembeek is a nice touch and was a matter of luck. Boon is only open to individuals to tour on Wednesdays at 3 pm.
Which segues nicely to my first conclusion for doing a Tour of Belgium. It's hard to get into breweries. Many don't do tours or do them very rarely, and others only do large group tours. For example, Duvel has a 15 person minimum and then the tours where closed when I checked back after a week at GALA in Denver. Huyghe responded with the same 15 person minimum.
The above list consists of those that do tours daily (Cantillion), on a regular basis (Het Anker, weekends), periodically (Boon) or me getting lucky with a nicely worded email (Bosteels). The Bosteels rep very kindly found me a single spot on a German language tour and I'm very much looking forward to the experience.
In short, combined with a personal rule of never driving in a foreign country with even a single beer, it's extremely difficult to get to Belgian breweries further a field without help. While I'm sure the Delerium Cafe and The Kulminator will quench my thirst for Belgian brews outside of Brussels, I can really see the value of doing a planned beer tour with a group that has efficient and chauffeured access.