Ludei is in charge of all of this, releases, announcements, etc. From what I've seen they do not communicate that often with Scirra. We need to keep on them in the forums, twitter, email, etc and just wait for it.
They were supposed to open source the plugin and basically leave it up to us, but as we know, Ludei doesn't share roadmaps with the public.
<rant>
Let's remember, they are a start up, with a small team, and they are giving us a free product. They only have one goal and that is to get another round of funding to keep going, so they are really targeting the product to investors or potential buyers, not us. I feel once the product is more stable or they get bought out, they will become more consumer focused.
</rant>
Ah, I see. I thought because the plugin comes bundled with Construct 2, they would be in contact with Ashley and the team. As for roadmaps, Ludei publicly responded to my Tweet telling me very soon and most likely last week. This means Construct 2 is being paid attention and they have a plugin that is ready to roll. Ludei have a bigger team than Construct 2, they're a startup in the sense they need VC funding to keep going, but they've got the resources to at least respond a little more.
It would be in Ludei's best interests to give developers the required functionality to leverage their platform because I know there are a lot of developers out there waiting for Google Play leaderboard support before they release their games (myself included). There will be a flood of games Ludei can use to bolster their portfolio, "Hey look at what all these people have made using our service and not Phonegap" more users equals a better chance of them getting more VC funding.