Happy to report that by only upgrading to Micro Python v1.4.2 on 2015-04-21; PYBv1.0 with STM32F405RG from v1.3.10 made it capable to transmit data to other devices with the same commands (note, using a MCP2562 transceiver):
>>> from pyb import CAN
>>> can1 = CAN(1, CAN.NORMAL, extframe=False, prescaler=16, sjw=1, bs1=14, bs2=6) # 125kpbs, PCLK1@42000000
>>> can1.send("321",123)
>>>
Still not receiving anything, is there a filter to accept EVERYTHING, and it is NOT the default?