My suggestion is to give a bit more time to 4.8 and the underlying platform to mature. I dont know when you want to release 4.8 but I would do it in 2 months so that all the issues have been opened and closed and the beta version is tested and tried. The tools I develop are still running on 1.4 and we'll start moving them to 2.0.
Yesterday, I noticed that putting a halt in the test code or in its path hangs pharo 2.0 image (I'll open a bug entry). I'm not sure if this is related to it:
But lets help make pharo 2.0 more stable before moving on.
usman