This is the XenApp 6.0 Hotfix you are looking for

Basically, this is just a quick update to my previous post on Citrix servers freezing.  In looking at the dates, I now realize that I have been waiting over two months for this hotfix!

Anyway -- the hotfix to resolve a LOT of stability issues was released this morning (XA600W2K8R2X64046) and can be obtained at the following site:
http://support.citrix.com/article/CTX128342

Happy patching!