You should be able to do this with a table filter, using a subquery (which means you'll have to be using the SVN version, as this was added since the last ZIP was built).
The problem is, you can't do straight '<' or ,'>' logic on MySQL dates, you have to use the MySQL date calc functions. And we don't (yet) provide any pre-built options for that. But luckily we can work round this with a subquery. So set your filter up thusly:
FIELD: your_primary_key
Condition: IN
Value: SELECT your_primary_key FROM your_table_name WHERE DATEDIFF(your_date_element,CURDATE()) >= 0
Eval: subquery
Although in SQL terms, this is slightly inefficient, it should work just fine. I tested it on my server, seems to work OK.
This should give you all rows where your_date_element is set to todays date or greater. If you don't want to include 'today', make it > 0 instead of >= 0.
-- hugh