Well like it or not electronic is coming to mountain biking and personally i am looking forward to it, i have heard as others may have that eletronic XTR is on the way and maybe within 2012, and i have heard from a source in the know that shimano have already planned electronic XTR, XT, STX and deore within the next seven or eight years, As people have said in this thread shimano generaly do good things and as of yet i havn’t heard of any problem with dura ace or ultegra di2, as for rapid rise it wasn’t a problem with the product as it worked fine the general public just didn’t take to the idea.
As for the battery v’s dynamo WTF you know how heavy those hubs are don’t you and the battery lasts 6-8 months and only takes 2-3 hours to charge and as someone else commented if you ignor the few hudred miles worth of low batt warning well you deserve to be stuck in that huge gear all the way home. ROLL ON XTR DI2.