I'll answer the original inquiry...
The Pentium M 1.6 will totally kill the new 17" PB at 1.33Ghz. How do I know, I have both of them and they aren't even in the same ballpark. (the 17" PB is provided by work and the T40p Pentium M 1.6 is my personal) When I received the new 17"PB, I tested it to see what I'd run on it and it is slow (it has twice as much RAM as the T40p too) compared to the speed of the Pentium M. You can try any crossplatform app you want and the results are always the same with the 17 lagging far behind (my second test was going through the Adobe suite of apps to see if there was any thing that would make the PB really perform... but came up with nothing.) The 17" in now just my "play" machine to try out all the OSX stuff (I have ADC) and a pretty paperweight.
As for wireless not being upgradeable on the T40, it's located on the miniPCI card which can be swapped out (of course, not going with an Intel solution, will make the branding non-Centrino-- which has never bothered me.) All in all, the Pentium M laptop is a real winner (it even slays the dual G4 running Panther Server.) Only problem now is that when we (myself, the IT dept, and fellow computer enthusiasts at work) went through all these tests, the IT group is a bit depressed since the dual G4 is only 5 months old and fully maxed and was supposed to be the server for one group for sometime. It doesn't look good to have that machine degraded by a laptop. The 17" was almost going to be returned, but the screen saved it (hey, it's still pretty!)
(An interesting result of the test was that running the Dual G4 1.4 in single chip mode, it outperformed the 17" 1.33 PB but just a smidgen at the same RAM levels (the systems were recalibrated out of curiousity) and both running Panther)