Hi!
I uploaded my latest modifications to collections to the inbox. The suggested load/merge order is:
Collections-ul.144 Kernel-ul.251 Collections-ul.145
To load/merge these packages, you should have both Collections-ul.140 and Collections-ul.143 loaded/merged.
Since the trunk doesn't have enough tests for the Collections package I decided to load these changes into the latest pharo image and run the tests. All of them pass, except for the tests for WeakKeyToCollectionDictionary, but that's because of a bug in the tests (The tests add SmallIntegers as values instead of Collections to the dictionary. Unfortunately they all pass with the original implementation, because #rehash is never sent to the dictionary).
To see if it's worth (or not) to use these changes I wrote a small benchmark for Dictionary which can be found here: http://leves.web.elte.hu/collections/ .
Cheers, Levente