Actually we have two physical Servers running the View environment. One server runs virtual server for the View Composer (1.1.0 build 161885), View Connection Server (3.1.2 build 188088) and license Server. On the second host only the desktops are running. Both physical server run ESX 3.5.
We would now like to move the virtual servers to our new ESX Farm running on VSphere and still use the "old" esx 3.5 Server for running the virtual desktops.
Will ther be any compatibility issues? Is there a compatibility guide to support me with information?
Shouldn't be any issues since ESX 4.0 is backward compatible with 3.5, you'll just have to upgrade VMTools on the virtual servers you migrate to VShpere. Whats installed on the vm's should be transparent to what hypervisor you're running. Your View licenses don't actually cover running virtual servers on the same ESX hosts as the desktops anyway so probably best you move them off unless you fancy purchasing more ESX server licenses.
Also you won't be able to upgrade to View 4 until you've upgraded your View ESX hosts to vSphere.