Sales of Verizon's Droid Incredible 2 start on April 28; Sprint will begin selling Nexus S 4G on May 8
B&N also launches developer program for Nook apps
50,000 units sold on Tuesday, says RBC analyst
Customers show the text to a sales clerk to receive a discount
With $300 price tag, smartphone also has unlimited data for $29.99
Carrier doesn't seem to matter much with first quarter iPhone sales
RIM focusing first on corporate sales, analyst says
Can be read on Kindle or devices with Kindle reader
Company says it's looking to meet enterprise customer demand
