The Thinkpad is refurbished, if that matters, and comes with a rather old OS. The HDD is on the small side on the Thinkpad too, but it does have a higher resolution screen. The Thinkpad looks to be more of a business/portale laptop than the Lenovo, although the Lenovo page doesn't mention the actual size (although I'd hazard a guess it's 15.4" widescreen) or some other important specs. Installed RAM and the atcual processor are also not listed - just "up to" 4GB, and 2.2GHz Pentium Dual Core respectively.
Just my £0.02.