Hey Bill,
Well with the mac you wont be limited to 8gb of memory (flash memory is now faster than standard HDs - it's also being made in chunks of 20gb+)... and actually having no windows is a bad thing!?!?!?!
Having said that of course macs will quite happily run windows as it will Mac OS X as well as BSD or another linux variant. Why take one OS on the road when you can take three?
The thinkpad is a really nice machine - no question. But having already trashed 2 hard drives on the road my next laptop is going to have to have flash memory.
Plus it'll come with all of those modern gooddies like USB 2 which will make the transfer of photographs significantly easier and faster, not to mention 802.11b/g so faster connections to the network when I do hit somewhere that needs it - mainly at home when I'm pushing the large photo files around.
But it's very much horses for courses with these things. I don't need massive HD because I drop my photos off in 4gb chunks and post them home - once I know they've arrived safe I drop them off the laptop - the last thing I want is to have the kit nicked or for it to break with ALL my shots from the trip on - so a massive HD is overkill for me.
For example on my last trip I had one of the first Samsung Q1 Ultra Portables with a 10gb HD and at no point did I come close to filling it. It's not my main laptop - it's my kit for the road.
Then the rest of the HD is just taken up with my silly scribbles about 'life on the road' and how tough it is

which, as it's text and uploaded to the blog all the time hardly takes any room up at all.
I'm not one of these people that takes films (movies) with them (what's the point!?) but I do like to have space to download useful doc / pdfs if and when I need them.
The nice thing about flash memory is how easy it is to upgrade / add to. If I need more space for something specific I just plug in an 32gb SD card (£120 from play.com) and I've instantly got more space. Or just a cheap £15 8gb jobbie from play.com.
I carry an iPod too of course and if I really need the space that has 160gb (40 taken up with my music) - but even though I love my iPod I still don't trust that it wont die on the road so wont put anything essential on there.
Now I think I'm rambled on enough and I should leave you to your breakfast!
m