As peculiar as the after-the-fact announcement of Google Bouncer may have been, it was still good news. Perhaps Google was ramping up, trying to make sure that its Bouncer would work as intended and be able to handle the flood of new apps submitted to the Android Market. Perhaps the company just wanted a head start so they could be ready for the malware writers who will surely try to test the system.
Regardless of the reason, the fact that Google has its Bouncer checking for apps with embedded malware is a good thing. Bouncer has several things it does when an app is submitted for inclusion to the Market. First, it scans the app for known malware, and if it finds any, then that app is blocked. In addition, Bouncer checks the app for suspicious functions that may or may not be malware and shuttles those off for manual inspection.
Google also runs every app submitted to it for use in the Market on a simulated Android device in the cloud to confirm that it behaves appropriately. If the Bouncer finds that specific developers are repeatedly sending in apps with Malware, it blocks submissions from that developer.
Google has said that its also in the process of checking apps already in the Android Market for malware. Its not clear how far along this process is, but at some point, Google will have ensured that that everything in the Market is malware-free. Unfortunately, that doesnt really end the malware problem for Android devices, although it does reduce the level of risk.