I suppose Boulogne becomes something of a nexus of English influence on the continent?
Does Stephen of Blois recover Normandy? It had been conquered by Angevin forces, and could pass to Henry's brothers Geoffrey and William. If they're ensconced in Normandy, or even just in Anjou, they could be a major headache for the Blois regime. If they get killed or captured in whatever action results in Henry's death then Stephen's regime is on somewhat surer footing.
The big question is probably who Eleanor of Aquitaine marries with Henry dead. Geoffrey supposedly made a play for her IOTL, I don't know what other likely candidates are about.