Performance-wise AMD isn't able to keep up with Intel these days but the firm still has hopes that its future processors will do better. According to FUD Zilla the first 45nm CPUs from AMD should be ready in the second half of 2008 and is called Deneb:
Deneb 45nm will support the existing socket AM2+ and it will work in AMD 790FX and the rest of the 7x0 chipset family while you will have to chance the motherboard to make the Nehalem work
Deneb 45 nm quad core should come before Nehalem as the latest roadmap we’ve seen indicates that Intel won’t launch its native quad core CPU until the very last Q4 2008.
We hope for AMD’s sake that Deneb will be out a bit sooner than that.