Short the Vcore circuit to ground and probably damage the motherboard.
... unless I've missed something, according to the datasheet I have for the "Embedded Write-Back Enhanced IntelDX4 Processor", those pins on the 168 pin PGA package are Vcc and Vss. I have no idea why anybody would intentionally tie those together. But if it was accidental, then that at least makes more sense. Good thing you caught it.
I realize this isn't exactly the same CPU as that document was written for, but since it's the same packaging, I doubt the Vcc/Vss pins are that different. I'm looking at Intel doc 27277103, page 10 (PDF page 14).