How to implement a taxonomy view? I would like to show a list of taxonomy terms and include:


number of nodes that are linked to this term
datestamp of latest node with author and title that is linked to this term


Can this be done in a view, or do I need a custom query?
From a performance standpoint, wouldn't it be better to save that info in taxonomy fields?
Try to create a View using grouping.

Set Format to Table 
Go to Settings > Grouping field = "Tags" (your taxonomy term field)

Field "Tag" should have this setting:


Exclude from display [X]


There are some modules I didn't try that could help you with adding summary field to your Views:


Views PHP (D6 + D7) or Views Custom Field (D6)
Views Calc (D6) or Computed Field (D7)
Views Group By (D6)
Views Summarize (D6)
Views Hacks (D6) (including Views Taxonomy Summary)
Views Taxonomy Edge + Taxonomy Edge (D6 + D7)
Better Exposed Filters (D6 + D7)
Taxonomy Views Integrator (D6 + D7)