I don't want to make promises I might not be able to keep. Some issues, like issue #100, will feature some other heavy hitter as the "super special adventure," and the Adventure Path will have tendency to usurp that roll (it's about keeping your eggs in different baskets). That said, I'll print them as often as I can and not overwhelm DMs running the campaign. Each adventure in the Adventure Path will run at least 32 pages (or one module unit), just like the Wizards of the Coast adventures, but we might run a little long in the later modules as stat blocks get longer and the adventures get wordier.
And yes, the Adventure Path is intended to be run as a campaign that takes characters from 1st to 20th level, so there will be a strong story arc, and lots of module to module tie-ins. At the same time, each adventure will be self-sufficient, so DMs will be able to pluck from the Adventure Path tree as they desire. I'm putting together an Adventure Path bible, actually, so I can keep track of all the names, places, and plots that give a campaign continuity.