What would the situation be had Coakley-D won the 2009 Special election instead of the Pickup Truck Driver? Coakley-D would have won the 2012 US Senate Race for a full first term due to Obama coattails.
Warren would have to hope that Governor Deval Patrick appoints her to Kerry's vacant US Senate Seat. Markey-D would remain in the US House.
Warren's 2018 sacrificial lamb Republican challenger is likely to be Mitt Romney.
Romney doesn't even live in MA anymore, he's shifted his primary residency to Utah.