Though the launch for Windows Phone 7 has been mostly positive than negative (777 apps so far but supply issues in Europe and Australia), there are a few holes left in the OS that are keeping certain developers from entering the WP7 field.
Two of those companies are Fring (past coverage) and Layar. The former is a VOIP/IM solution familiar to Windows Mobile users (they offered the best Skype experience before their falling out) and Layar, offers an "augmented relaity" app for finding local happenings.
The issue for both of them is lack of access to the camera: Fring for video calls, Layar for its camera/GPS combo that allows you to "see" locations in your surroundings. For Fring, they don't need the camera, but after entering the video chat market big time with the EVO 4g, not having access "cramps their style" and of course with no camera, there is no Layar. Layar had this to say about the issue: "On our side, we don't really understand what this means or why [Microsoft is] doing this" and Fring was also as direct: "We need the ability to get to all the different parts of the device. We need to have that freedom. There have been standards set by Android and the like. When the cards are held too tight, it cramps our style and we can't deliver the value that consumers want and expect from smart phones."
Evidently, Microsoft is mum on the issue. Is it because the API is not ready? Do they plan on addressing this soon in a developer tools update? Or is it verboten indefinitely? We'll keep following the story for any changes.