It's great to hear that finally gapless playback should be possible. I followed the instructions and installed the walkman package. Starting causes always a crash. When I look into the error messages with logcat, I see that it complains about missing classes regarding ClearAudio+. AudioEffectService.apk is installed, so CA+ should be available. I am wondering if this package should also be updated? (btw. I am running a stock JB with firmware 6.2.A.1.100).
Looking forward to solve this (I assume others also suffer from this, but did not look into their log).