Step 1: Go to Wizards' site.
Step 2: Read the years of archives of free adventures, errata, sneak peeks, minis scenarios, entire small supplements disguised as 'web enhancements,' etc.
Step 3: Profit!
Seriously, the basic e-zine type content on Wizards site is already there to see, and it's been outstanding for years. Their d20 system games (D&D, d20 Modern, Star Wars and the two d20 minis games, Star Wars Minis and D&D Minis) collectively get a magazine's worth of content every month already. Likely add what you get from Dragon to that (most of the writers being the same). I'm not sure how much they'll expand the adventures.
Wizards' site for their flagship product, Magic the Gathering has two magazine-suitable articles published every weekday. If they have that amount of content on the d20 side when the new version goes up, it will be well worth buying.
That's why I'm enthused about the prospects of this move - half the time, Wizards has been pumping out better content for free on their site than they put in their books. If they can expand on that, maybe get the regularity in the d20 side they have in the Magic side, complete with theme weeks, their site could be the most spectacular gaming resource around.