David Chalmers will be there talking about uploading. The Summit is branching out into topics like biotechnology and decision theory instead of just robotics and AI. Peter Thiel, who backed SENS (Strategies for Engineered Negligible Senescence) with $3.5 million in funding, will be speaking as well.
Ned Seeman [Prolific DNA Nanotechnology pioneer], Robin Hanson and many others will be speaking.
Here are highlights of the 2008 Singularity Summit.
Kurzweil AI has some information as well.