The interesting thing is from this PDF article from the October 28, 2002 issue of Microprocessor Report, which quotes IBM's estimated SPECint2000 and SPECfp2000 scores for the PPC970 at 937 and 1051 respectively. And that's the 1.8 GHz part, not the 2.0 GHz part; if we extrapolate those numbers to 2 GHz, we get SPECint2000 1041 and SPECfp2000 1167.
Since we're using IBM's scores instead of Apple's for that side, we'll use Intel's scores instead of Dell's for its side. Intel's scores for the 3.06 GHz P4 are SPECint2000 1088 and SPECfp2000 1077.
Which would actually put them both in about the same league, with neither side able to claim "our processor stomps your processor." So everybody put a sock in it.
(For the record, in case someone asks, AMD's scores for the single-processor Opteron 144, their fastest single processor part, are SPECint2000 1170 and SPECfp2000 1219. AMD quotes peak rates, while the others are quoted in base rates.)