Just a few notes about XenApp 6.5:
First if you where a custom to using Load Evaluators for managing Servers Maintenance Windows or taking servers offline you better start getting use to Worker Groups. The Reason is they have moved Load Evaluators to Machine Policies so you can't change them on the fly, with this being said I highly recommend using Worker Groups based on Farm Servers instead of OU. This is so you can easily add and remove servers this taking them out of the published application.
Second, Licensing is a Must, but again this is done through Machine Policies. You have to select the right Version (Adv, Ent, or Plat) Also a new feature is you have to select your licensing model (XD or XA, Concurrent or Named). Note: if you run the following command qfarm /load and get a load of 20,000 you don't have licensing set correctly.
That is mostly it for now, just wanted let you all know of the few changes. More to come...
Thanks for reading