One of the features which Tobias has been working on lately that I appreciate a lot is the Help Center.  What do I like so much about it?  There is no static compilation step!  This means the list of cmdlets which you see matches the snapins you have loaded at the time.  I add new snapins all the time so I find this extremely useful when I need to look up a parameter.

I’m not sure if the currently available beta builds work exactly this way–they might.  Another cool feature not shown is an Office-like text box in the toolbar in which you can type cmdlet names to pull up the help.