No, you can't update Lenovo ThinkPad T61p drivers from www.nvidia.com, but you must update them from www.lenovo.com; the newest drivers support even OpenGL 3.2.
The T61p works fine with LE (I have one too), and its nVidia FX570M is amazingly powerful. It's much faster than the 8600M in my Asus laptop, and only slightly slower than my 8800 GTS 640MB.