I was just upgraded from my old T60 (acquired in November 2006) to a brand new wide screen T60. Definitely an improvement over the old T60.

Pros

• Next generation CPU's (Core 2 Duo rather than Core Duo)
• Faster clock speed (2.33GHz instead of 1.8 GHz)
• Slightly better video card (ATI x1400 instead of x1300)
• Wide screen
• The brightness of the screen has significantly improved
• Speakers are now on top of the keyboard rather than on the bottom of the laptop (Who thought to put them on the bottom?!?!?)

Cons

• Hard shutdown on dock problem still exists (I guess it really is static on the dock)
• The new screen seems to be more sensitive to viewing angle

Other than that everything seems to be pretty much the same.