"From my readings on the G4 Mini, the processor was soldered on, which prevented a user from going from a 1.25ghz G4 CPU to a 1.42ghz G4 CPU. Such is no longer the case with the Intel chip. Someone has already upgraded their Mini to a 2.16 Core Duo processor; read about it here. The link offers a variety of photos; no installation video is available as of yet."
If you can somehow get the intel chip out of your mac mini your next issue will be whether or not the motherboard architecture can support the chip...Might be cheaper to just buy a mac mini with an intel already installed.
It won't work. The most basic bit of code in the system, like the firmware used to boot, is processor dependent. So even if you could make the pins fit (which they won't, but just for fun) is would not work.
On the bright side: If you buy the cheapest intel Mac mini, you can buy the highest end Core 2 Duo notebook processor in a couple of weeks and simply plug it in. Apparently, Apple's made it rather easy to upgrade the _new_ mini. I'm looking forward to reports of people who bought an intel mini when it came out who think about upgrading it. (There were a couple of reports about this a few months back...)