With the release of Update Rollout 9 for Exchange 2007 SP1 comes a new version of eseutil. This new version has a new arithmetic for verifying transaction logs which is now much faster. Microsoft has written a knowledge base article about this which can be found here:
Another change in Update Rollout 9 is support for Server 2008 R2 domain controllers. Note this support does not allow Exchange 2007 to be installed on a 2008 domain controller, only authenticate against them.
This will be the last update rollout of Service Pack 1. The next release is Exchange 2007 SP2 which is going to contain all the fixes in the past 9 update rollouts as well as additional features within the exchange console & shell and support to intergrate directly with Exchange 2010.