This sounds wonderful; I'm a fan of organized play when done right, and I think that WotC can do it. I loved running Encounters, and we got a pretty great turnout (at least 2-3 full tables a season), but I know every DM there was pissed when we had to start buying our own modules. We were already spending our time prepping and running the games because we love to play and bring people into the hobby, and charging us to be the marketing arm was too much.
I do hope they break the exclusive ties to Forgotten Realms, though; I know it's a popular setting, but there's so much more to D&D than the "fantasy kitchen sink" of FR. The Dark Sun Encounters season was really popular because people didn't know there was such a thing as post-apocalypse D&D, and they were excited to try it. Having an occasional Encounters season, Expedition module or Epic event in a different setting would show off the variety of D&D, and be a great selling point for the inevitable books about those settings.
Also, here's hoping that they tie these "adventurer logs" into an online system where people can build characters, trade items and learn about factions. Online support from WotC has been severely lacking, but setting up a system here could do wonders to keep people engaged in the events, help them find groups, encourage them to buy splatbook X for the upcoming Epic event, and act as a gateway to paid D&D Insider subscriptions.
EDIT: Read the entire thing on the WotC page, and now I'm both excited and confused.
Progression and Rewards
All D&D Adventurers League play is supported through a certificate system. Some items and rewards are only awarded through certificates, but the main purpose of the certificate is it unlocks the ability for you to trade the item to another character. Magic items are rare and special treasures in D&D Adventurers League play, and we want them to feel as such through representation as a cool certificate.
Since when has magic been rare in the Realms? There are +1 swords all over the place, wizard guilds in every major city, and the literally thousands of adventuring parties that roam the Realms all have at least a wizard and cleric. I get what they were going for with rarity, but either they are only counting epic level items or people are going to have bricks of certificates in about a year's time.
Advanced Play: D&D Expeditions
If you like a deeper dive into a "convention-style" campaign experience, then D&D Expeditions is for you. Set in the Moonsea region of the Forgotten Realms, you'll explore the storyline as it affects the denizens of that area of Faerûn. Here, you'll get to take your character from its humble beginnings to the heights of high level play, and have a chance to really influence your region through your character's actions and the actions of your faction.
Adventures are delivered digitally as PDFs to stores and conventions requesting them, and debut at selected conventions around North America throughout the storyline. If you play in a debut of an adventure, you'll have the opportunity to give feedback and shape the ongoing storyline. In addition, these adventures will be supported with kits that contain the certificates for the magic items and other special stuff that characters can earn through play.
We expect that D&D Expeditions will become the public's D&D campaign, growing and changing as events resolve and new threats emerge. Each storyline visits a different area of the Moonsea, affecting some change there, and all the factions are involved. For Tyranny of Dragons, we'll be setting adventures in and around the town of Phlan, an old fan-favorite from the days of Pool of Radiance.
Reading between the lines, it sounds like Encounters going to be taking a backseat to the Expeditions, with the former serving as a springboard for the latter, and quickly discarded. That's an interesting move, because it means they are expecting enough new players or old hands who like low-level play to keep Encounters running simultaneously as weekly events (it says that Expeditions encounters are available on request, and if they want it to be the public face it can't be convention-only or limited to a couple of adventures a year).
Honestly, I'm not sure what the advantage is for setting it up in three categories; my own two cents, I would have set up Epic as the special event games, and kept Encounters as the ground-level campaigns. It's easy enough to run games set in the 5th Edition version of the Heroic tier (first 10 levels), and that way you maximize the chances of getting a full table of both old and new players, with the module and table demographics adjusted to provide a suitable challenge for everyone. That way, new players don't feel like their playing the training-wheels version, but instead are right in there, having fun with the experienced players and forming the social connections to get them to be regular players (read: regular consumers of RPG products). Meanwhile, the characters carry over and can be used for multiple seasons and at these Epic events, giving some nice continuity.