I think, it will be very good if IT Services evolutionate to sophisticated datastructure with a lot of "magic":
1) Each ITService must be associated with some Zabbix object directly (including ITService itself).
2) ITServices must be linked together in the directed graph - extended form of the simple tree which can contain ITServices-associated-with-other-ITServices
3) ITServices can be manually or auto-provisioned. For example ITServices-associated-with-hosts can be created under the ITService-hostgroup automagically - and, if desired, in the same way ITServices-triggers can be autoprovisioned under ITServices-hosts
4) ID of ITService will be "universal zabbix object ID": first 8 bits of ZOID represents Zabbix object type associated with the service and last 56 bits (on 64 bit arch) - unique number of Zabbix object (such as hostid) inside the group.
1) Each ITService must be associated with some Zabbix object directly (including ITService itself).
2) ITServices must be linked together in the directed graph - extended form of the simple tree which can contain ITServices-associated-with-other-ITServices
3) ITServices can be manually or auto-provisioned. For example ITServices-associated-with-hosts can be created under the ITService-hostgroup automagically - and, if desired, in the same way ITServices-triggers can be autoprovisioned under ITServices-hosts
4) ID of ITService will be "universal zabbix object ID": first 8 bits of ZOID represents Zabbix object type associated with the service and last 56 bits (on 64 bit arch) - unique number of Zabbix object (such as hostid) inside the group.