The timing of the teaser dovetails perfectly with an earlier leak from Verizon, saying that Android Pay would debut on September 16th. However, another rumor that we told you about last month suggested that Android Pay would launch at the same time as the new Nexus 5 (2015)/Nexus 5X because of the fingerprint scanner on the phone. That handset is rumored to be unveiled on September 29th.
Android Pay will use virtual account numbers in place of credit card numbers in order to maintain safe transactions. And because the service shows you the exact time, place and dollar amount of each transaction made using Android Pay, you can quickly spot any fraudulent activity on your account. Should your phone get stolen or lost, using Android Device Manager will allow you to find the handset, lock it, or even wipe it.
If the Android Pay app is handling mobile payments, what will Google Wallet do? The latter will be relegated to handling money transfers. It will also still allow you to use your Google Wallet card along with the app.
source: AndroidGuys