I think that there is a real need for a site like this. Mobile web development is a subset of web development in general but it isn't currently given much coverage by the big web development sites like Webdesigner's Depot and SitePoint.
Coders is new and doesn't have a huge amount of content yet but there's some good stuff like a recent post on using the Google Maps API to display maps on a mobile site. I'd classify the articles on Coders.mobi as beginner to intermediate level but definitely worth a look for anyone building mobile sites. I hope David Wiles, the developer behind Coders, continues to add useful mobile development content and features to the site.
Ratings: Content Usability
Ready.mobi Score: 5 "Good"
Mobile Link: coders.mobi