There is another Agenda wannabe. It's called orGenta. It has the look and feel of a real spreadsheet. Since "orGenta stores your Items and Notes in a Microsoft Access database, ... you may run queries in Access, or link to your data in Excel."
orGenta has automatic category assignment and "smart date recognition." I tried it and found it less than intuitive. This may have had to do with the fact that I did not give it enough time and the "feature" that "items get assigned" to categories "in the 'background': you may not see them applied until you expand or contract the TreeView." I found that disconcerting.
I mention it here for completeness' sake, as I have talked about other Agenda-like applications before. In many ways, this is the most "faithful" to Agenda as a "spreadsheet for words." If only it would look less like a spreadsheet.
It's shareware and costs $10.00.
There has been no development since 2006, but it might be worth a look for hard-core Agenda aficionados. I do not belong into that category (no pun intended).