All the details can be found on the Official MDOP blog and here on the main virtualization site.
APP-V 4.5 CU1 is now available as part of MDOP 2009. App-V 4.5 CU1 adds support for Windows 7 beta, so customers can move ahead with application testing in preparation for enterprise deployments. It also contains a few improvements such as instant access or removal of applications assigned to end users.
AIS 1.5 update, now available to all MDOP end users through Windows Update, enhances the license reconciliation feature and the task scheduler. It now provides a detailed report for each application (e.g. whether license type is retail or volume license) to simplify license inventory tasks and to improve licensing compliance. The inventory scan scheduling has been improved to ensure data is collected even from devices that are turned off regularly.