Hi I recently imtroduced some young deaf people to skype and they had a great time using sign language to communicate with each other across a college campus. This is such a brilliant possibility to widen the communication possibilities for deaf people as long as internet strength is good enough. Currently it is possible to have audio only...could it also be possible to have video only...if not currently possible...might skype consider this possibility to make it accessible to deaf people.
Skype decided to not address this issue as noticed here
My simple advice is to use OOVOO!!! oovoo is popular with deaf people because it does not require sound!!