I'm rocking out an i5 at the moment

All Lynnfield cpu's are 2.5G plus 4-core processors and fairly chunky L2 and L3 caches.
Also:
does anyone know anything about the new Intel chips (the i-series, i3, i5, i7) and how they compare to the Dual Core and Core-2 processors?
so i'm quite tempted to get a Dell studio as then I can get this cover
not sure i can justify the extra £90 for it though