In JDK 8 with lambda b93 there was a class java.util.stream.Streams.zip in b93 which could be used to zip streams (this is illustrated in the tutorial Exploring Java8 Lambda
Using the latest Guava library (for the Streams class) you should be able to do
final Map result =
Streams.zip(
collection1.stream(),
collection2.stream(),
AbstractMap.SimpleEntry::new)
.collect(Collectors.toMap(e -> e.getKey(), e -> e.getValue()));