The latest x10 mini firmware news from the XDA forums is as follows:
Ginger DX v15 – lightweight based on Gingerbread from the CM nightlies
MiniCM7-2.1.1 – based on Cyanogen(mod) 7.1 ‘for the true CyanogenMod Experience’
MiN-06 | Clipped Stock Eclair 2.1.1.C.0.0 – A stripped down stock firmware
E10 SonyBread Seven SP3f – MiniCM with lots of Sony Ericsson Xperia Apps and theming
Cyanogenmod6 MIUI – MiniCM6 made to look like MIUI
If you’ve tested or use any of the firmware listed please give feedback to other users via the comments.