stream, opencl, app acceleration...http://developer.amd.com/zones/OpenCLZone/Pages/default.aspx
on the basis of this i will go for 7000 rather than 600 series of nvidia...... if not then i will go for 600 sires.... because i m preparing to go for new card when it will available in market .
if you want to compare between the two series, wait for the 600 series to launch and get tested.
nvidia's physx is just another technology for physics calculation. cpus can do that too (slower than gpus). it isnt widely adopted. most people can do without physx.
amd's graphics core next (gcn) is their new architecture to compete with nvidia's current fermi and future kepler (nvidia's architectures) cards.
beating.. that depends on many other factors such as performance, optimization, driver support, marketing, developer relations etc. look into in depth, analytical articles on quarterly and yearly earnings of each company.