The Host Integration Server Product Team has just released the second Cumulative Update (CU) for HIS 2010. The cumulative update model is used to package and release product fixes on a more consistent schedule.
HIS 2010 CU2 includes fixes for HIS 2010 that were fixed after the release of HIS 2010, including all the fixes that are in HIS 2010 CU1. Details on the included fixes can be found in the following Knowledge Base article:
2616519 Cumulative update package 2 for Host Integration Server 2010 http://support.microsoft.com/default.aspx?scid=kb;EN-US;2616519
There are some additional fixes that are not yet listed in this KB article because the KB articles for those specific fixes are not yet completed. Once these other KB articles are completed, article 2616519 will be updated to include links to those articles as well.
One of the key features included in HIS 2010 CU2 is the support for 32-bit SNA applications (such as 3270 emulators and APPC applications) on 64-bit versions of HIS 2010. This particular feature will be detailed in KB article 2532670, which should be available shortly.
You can download HIS 2010 CU2 via the View and request hotfix downloads link in the KB article. You would need to download the CU2 package that matches the HIS 2010 version (x86 or x64) that you have installed.