Of course, if we were all running 64-bit OSes with 4-8 cores having 16-32 GB RAM, we'd see a different story altogether (hello on-board memory controller, dynamic scaling, ect.). However, we are talking about mobile computing here. Intel has always owned the performance crown in mobile computing (well, maybe except for a breif period between the P-III Tualatin and the Pentium M) and even more so since the Pentium M-- more performance at lower frequencies consuming far less power than any of the competition.
The introduction of the Core and Core 2 has done nothing more than solidify that position. . . and if it's just $20 or so price difference compared with comprably performing AMD parts, you go with Intel if you primarily value performance.