I'm just curious. Of the people out there using 64bit jvms, has anyone run into the int collection size problem? One of the things I've been quitely worried about for awhile now is that with both 64 bit jvm's and the virtual heap stuff provided by Terracotta DSO it is possible for an ArrayList or a HashMap to grow beyond what an integer can hold. Sure 2 gig of objects is a ton to be in a collection but if one has a 128g heap it isn't crazy anymore.
It's easy to make the collections able to handle the larger sizes but so much code is written to the current collection interfaces it might be a problem. Have the smart people at Sun started tackling this already? Maybe some JSR?