2nd or 3rd gen. Intel Core i3, or i5 laptop

First generation i-series processors are no longer sold in Dell systems, so if you buy one today, it will be second generation i-series.  There is no such thing as a "third" generation i-series right now, but we'll see what happens to the naming when the Ivy Bridge processors are released next week.  It will likely be several weeks to months before you see one in a Dell system though.

In general,

The current second generation Intel Core Processors start with 2XXX in the model numbers (i.e.; i7-2860XM or i3-2357M)

The soon to be released third generation Intel Core Processors start with 3XXX in the model numbers (i.e. - i7-3920XM or i3-3317U)

See the full list of Intel Ivy Bridge Processors at

http://en.wikipedia.org/wiki/Ivy_Bridge_(microprocessor)