You have to decide what to do with your applications. If you have an Android version, one option is to repackage the APK to a BAR using the provided tool set so that it will run under the Android player. There are many good Android applications that provide an acceptable or even good user experience this way. Another option is to port your BlackBerry Java application to Android (if there is no existing Android version) then package the Android version for the player. This would also allow you to market the application to Android users. The final option is to port the BlackBerry Java applications to the Native SDK, Cascades, HTML5 or Adobe Air.
The best way forward depends on how tightly integrated into the BB10 system you want to be. While there are facilities provided in BB10 that are the equivalents to those is BlackBerry OS, there have been significant changes required to enable the improvements everyone wants to see on the new platform. If you see BB10 as a significant part of your future business then porting to Cascades would be very worth while.