Brian Chen posted an article on Wired's website late last night where he said:
Retail giant Amazon is preparing to launch its own app store on the Android platform on Tuesday, March 22, a trusted source told Wired.com.
Looks like he's(but a couple bucks richer).
My guess was based on the announcement that the Amazon Appstore had an exclusive on the latest edition of Angry Birds. AB: Rio is scheduled for release next Tuesday, and if it's going to be available to buy then Amazon's Appstore has to be open. And then with the, I really thought it was going to launch by Friday. But now that we have a more definite date, this could get interesting.
I don't see a need for another Android app store.There already are several, and at least 1 is very good (SlideMe). That being said, Amazon will almost immediately become the second most popular app store, and this will happen simply because they are Amazon. They have a dominant position as a web retailer that no one can beat.
There's even a chance that Amazon could give the official Marketplace a run for its money. Amazon have forgotten more about retailing and customer service than Google will ever know. CS is one thing that Google simply cannot do; they prefer to build monolithic entities and then ignore the buzzing noises around the edges.
I'm not sure if anyone has thought of this yet, but I bet the Appstore won't be available worldwide. Kindle apps aren't, and I'd guess that Amazon will apply the same restriction.