Infinispan 5.1.0.ALPHA2 "Brahma" is out now containing a consolidated push-based approach for both state transfer in replicated caches and rehashing in distributed ones. The new changes don't have great impact on the distributed cache users, but for those that relied on state transfer, it's definitely good news :). State transfer now works in such way that when a node joins, all nodes in the cluster push state to it, rather than the new node getting it from the cluster coordinator. As a result of this, the task of providing the state is paralellized, reducing the load on state providers.
On top of that, this Infinispan release is the first one to integrate JGroups 3.0 which brings plenty of API changes that simplifies a lot of the Infinispan/JGroups interaction. If you want to find out more about the new JGroups version, make sure you check Bela's blog and the brand new JGroups manual.
Please keep the feedback coming, and as always, you can download the release from here and you get further details on the issues addressed in the changelog.