Underneath its new veneer, Triton has been completely rewritten from the ground up to support advanced communications services such as Voice over IP (VoIP) Internet telephony.
More specifically, AIM will directly connect with AOL's Internet Phone Service. Triton will not be able to dial out at this time, but that capability will arrive in a future iteration of the client.
In other words, Triton will bring half the functionality already offered by Skype. Now if only I knew someone who used Skype!