Well, the learning curve seems to be rather steep when it comes to OpenOCD + USB Blaster (+Eclipse&GDB +Cortex-M3).
Now my CPU is recognized, but there are some issues concerning JTAG speed (it’s soooo slow at the moment) and also reset.
I just implemented a crude speed setting, but I did not yet verify the actual speed with my scope. First I have to track down a reset issue (hey, good time to implement usb_blaster_reset - isnt it? 
)