TechCrunch: Android In-App Payments Coming Soon — Were Delayed Because Developers Were Busy
I don’t buy that excuse.
This comment by “MegaBert” sums it up nicely:

Google has conditioned its entire end user base that anything on the internet is free: email, Office-like applications, maps, operating systems, storage for video and photo– basically anything with a Google logo. Aside from any technical problems, this makes it difficult to sell apps or content on Android.