I got bPhone today and the Dimension Today working on 4.2.1 for the 8703e.
I downloaded the latest build of 8700 software from T-Mobile Europe.
Blackberry
(Direct Link doesn't work) :(
Select: UK, Free Download Area, Devices, RIM Devices, 8700 4.2.1 rel 180, then 8700M_PBr4[1].2.1_rel180_PL2.3.0.86_A4.2.1.108.exe.
Take the net_rim_theme_bbdimension_today_320x240_w.cod from C:\Program Files\Common Files\Research In Motion\Shared\Loader Files\8700-v4.2.1.108_P2.3.0.86\Java and copy it to a different location (I used my desktop because I was lazy).
Use javaloader to load it to your device:
JavaLoader.exe -u load net_rim_theme_bb_dimension_today_320x240.cod
My device rebooted automatically after the load. Upon the OS loading, I now have the today theme as an option, and bPhone can be activated.
I have javaloader.exe since I have the JDE installed for Blackberry development, but I know that I've seen it online by itself.
Kormac