As odd rumors go, RIM engineering the BlackBerry PlayBook so that it can run Android apps sounds pretty far fetched, but that's today's mystery. According to "multiple trusted sources" speaking to BGR, RIM is considering using the Dalvik Java virtual machine, as used by Android, and potentially opening the door to the PlayBook and other QNX-based devices to run Android code.
RIM needs a Java VM so as to provide legacy support for QNX-based devices like the PlayBook, such as custom apps which corporations might have deployed and don't want to - or can't - recreate as a native version. Official access to Android apps would be another thing, however; that would require RIM working with Google to certify its platform in some way, so as to provide official support to the Android Market.
That sort of agreement would likely work in RIM's favor, but whether it's something Google would be amenable to remains to be seen. Still, as we saw in our own hands-on time with the PlayBook, there's a lot to like about the BlackBerry slate, and Android support would be icing on the cake.