Although the whole of Legend is released under the OGL, it would be nice to see updated versions of the remaining MRQ II books - for example, Empires and Necromantic Arts. When the Glorantha-specific material is removed, it is possible to bulk these out with relevant game mechanics from Elric,Hawkmoon, Lankhmar, and Wraith Recon. There's also a wealth of MRQI material that could be converted in a generic fashion. And that's not even considering the volume of d20 material that could be reworked for Legend.
Perhaps a short-term approach might be to look at things like the Earth Power section of Slaine and consider releasing generic versions as short PDF-only releases. A slow feed of brief PDF releases would be better than the long delay we are seeing now. It would be fantastic to see the backlog of works currently stalled in development hell released to the world, but given resourcing constraints and the popularity of Traveller, we might not see them for a while. So maybe the answer is to release some shorter PDF works to keep the game alive until the production queue clears a bit?
As for a new OGL game based upon Legend, I suspect there is a place in the market for a d100 game with a complexity level somewhere between OpenQuest and Mythras - perhaps a bit more "crunchy" than OpenQuest, but not as "crunchy" as Mythras. Such a game could serve as an entry-level introduction for new players - now that Chaosium's Magic World is dead, nobody is scratching that particular itch. Mythras Imperative comes close, but isn't a complete game system with a supporting product line - it's designed to push you towards it's big brother. And although the upcoming Chaosium version of Runequest may hit the right level of complexity, it will be very tightly integrated to Glorantha. Mongoose had the right idea by pricing the PDF of the core rules so low to encourage newcomers to pick up the game, but never developed a coherent strategy around that.
Althernatively, Legend could be tightened up to focus on a particular style of fantasy. At the moment it's aimed at generic fantasy. But the Xoth releases showed that it does Swords and Sorcery very well, so why not focus the game on that particular sub-genre to differentiate it from its peers - Mongoose has a wealth of Swords and Sorcery rules content that could be adapted from the defunct Elric and Lankhmar product lines, plus the old d20 Conan line. (I'm working on my own homebrew variant along these lines under the working title "Savage Legends" - I'm aiming for the sweet spot between classic Swords and Sorcery and midern grimdark / dark fantasy).
To be honest, I suspect Mongoose has never quite known what to do with Legend. Given the low sales of MRQII, they released Legend under the OGL and gave it a low price point to stimulate interest. But I suspect that the initial surge of interest took them by surprise and they haven't really worked out what to do with the game. However, there is still an opportunity to position the game in the market in a way that clearly distinguishes it from the other d100 games out there.