From what I recall, WinMo 6.5 doesn't have any improvements to the basic calendar. However, if you want a better calendar that's skinned well and shows improvements in TF3D, you will see one w/ the 2.5 update.
The new calendar tab is in the following youtube video-
http://www.youtube.com/watch?v=CkP0n...eature=related
It'll have new displays like weekly, agenda and year, and even goes far enough so that when you make a new appointment..it'll all be done within TF3D. Pretty much, you'll never see WinMo's calendar again.
To get TF3D 2.5 though, we'll need the Hard SPL to be unlocked. Once that's done, I'm sure we'll find tons of cooks putting TF3D 2.5 into their ROMs, which is what most of us users on this forum are looking forward to anyways.