I guess he means that, at the end of a run, you'll end up with a chord that will want to 'resolve' to a chord that will be different from the one you are starting from, and you'll be able to consider that chord the root for a new key. Repeating the same pattern in the new key (transposing) will enable you to take another step, and so on and so forth.
For instance, you can have a simple movement like (just making this up): Imaj7-iidom7-Vdom7-Imaj7-vidom7-VIdom7.
If you start off in the key of C, those chords translate to: Cmaj7-Dmin dom7-Gdom7-Cmaj7-Amin dom7-Adom7
At this point you can resolve your Adom7 to a Dmaj7, and think of it in as the root of a new key: D. You can then repeat the pattern above moving everything up a tone to: Dmaj7-Emin dom7-Adom7-Dmaj7-Bmin dom7-Bdom7. At this point you'll be able to move to the key of E - you can continue as long as you want.
Now, this is probably not the progression key-wiz meant - but I think the concept of having a basic pattern that 'prepares' for another key is what he meant.