I get the sense, from all the mentions throughout the process of D&D Next, that Dragonlance remains on the designers mind for 5th Edition. However, I also get the idea that the reason that it's not on the top of the list for release is that they want to find a proper niche for it. As well-designed as everything in the 3.5 MWP material was, I felt that much of it could have been any faux-medieval world rather than Krynn.
Good point, and one I would like to address.
Back in the day, Greyhawk, Dragonlance, and the Forgotten Realms were referred to as the Big Three. Even in Spelljammer, we saw how their crystal spheres were a major triad in the setting. There were the Wizards Three in Dragon Magazine, one wizard from each of these settings. Likewise, many classic D&D games were in the world of Mystara, which shares many themes with the Realms.
The problem is that Greyhawk, Dragonlance, Mystara, and the Forgotten Realms fill a similar niche. The Forgotten Realms have the luxury of being the most widespread and popular of all these settings, ergo why it is on top.
Greyhawk is mainly known for its dungeons, and quite honestly, those can be placed in any number of worlds. We saw some of that with the Nentir Vale. Heck, the Nentir Vale could be added to any number of settings. While I think Greyhawk will always hold a soft nostalgic spot on many gamers' hearts, I don't see what niche it has to offer.
Dragonlance as a game world has similar issues. Many of its themes are transportable. The Knights of Solamnia? You can obtain the same themes from the Purple Dragon Knights of Cormyr. Wizards of High Sorcery have seen a generic version in the Mage of the Arcane Order. Kender were borrowed from for the 3e halfling. Tinker gnomes seem to have emigrated to other settings.
What does Dragonlance have?
Dragonlance has story. While it did okay as a gaming world, its success has always been as a novel world. Dragonlance's golden age of gamng was when the games followed the novels. When WotC decided that novels must follow games in 4e, it was the death of DL.
To Wizards of the Coast, I submit that Dungeons & Dragons is more than about games. It is also about story. Not every product has to be game-driven. Dragonlance has a rich history of storytelling, and is at its best when about a group of heroes who are more than mere companions; they are family. A Dragonlance novel line is a viable product.
As for Dragonlance as a gaming property...as much as I would love to see a DL game line again, I have another plan that I think is more viable. Make Dragonlance the story-driven adventure path setting. Take a page from Paizo, and have story-based modules with world info as other chapters.
Dragonlance can live again. There is a formula for success. WotC has but to take the first step.