For the love of I6, if they go the V6 route they'd be selling out their very soul! A BMW is supposed to be all about a smooth-as-butter-yet-strong-as-stroh-rum inline 6 (if we're talking 6 cylinders here).
Sure, V6 is shorter therefore needs a shorter bonnet, but again, BMWs are supposed to have longer bonnets than it's competitors.
Besides, what technical advantages does a V6 have over an inline? Really now? Crankshaft maybe isn't as flexible (not necessarily a bad thing) and it's shorter. Gee.
An inline 6's advantages? Where should I begin? It's smooth, it sounds friggin great, has more power strokes, IT SOUNDS FRIGGIN GREAT etc. etc. etc.
BMW, if you're reading this, take note: The day you produce V6s is the day I become a Merc fan...