I usually don't log in to post, but I haven't seen anyone point this out yet: Lenovos have high list prices, but there are ALWAYS coupons with >10% off of list price - frequently the coupons go up to 15 or even 20%. If you manage to get them at the outlet, you can often get them for even more off - 30-40%, and if you go for refurbs, the savings are even higher. While I know it's possible to get mac refurbs for under the list price, the savings on thinkpads are undeniably more plentiful.
That's one point - the other is general design. A lot of people in this thread are discussing features that only macs have. However, there are plenty of features that are matched (or exceeded) by thinkpads. For example, thinkpads also stop the hard drive automatically if acceleration is detected, and also have a spill-proof keyboard (which macs lack) as well as a significantly stronger chassis (aluminum frame INSIDE a magnesium-composite clad exterior).