We want to try to prevent as much regressions as possible (hopefully some of the bugs will still be fixed). There is no easy way of mixing the two versions. If you want it you need to compile one of the versions (likely 1.0.1) by hand and use some scripts to launch the old version. Further I would use different Wine prefixes for 1.0 and 1.2 (else Wine takes long to startup when you swtich between the two).
