My startup, AppStoreHQ (http://www.appstorehq.com), has been private alpha testing a mobile web app (HTML5) app store for the past couple months. It's been working out great and having Google come in for standard web apps should be a big wind in our sail, I think.
Our mobile web app store focuses on distribution and monetization of developers' work.
Here's an example app (it's an HTML5 frontend to foursquare) called fortysquires:
And it's purchasable from AppStoreHQ: http://www.appstorehq.com/fortysquires-mobilewebfoursquarecl...
It's also open source (so you can see how simple the API to interact with us is): http://github.com/iseff/fortysquires