If a 3520 is due the HIRE Act signed by the President on March 18, 2010 changed the minimum penalty to $10,000 per form.
If an 8621 is additionally due because the investment is a PFIC the HIRE Act signed by the President on March 18, 2010 changed the minimum penalty to $10,000 per form.
I am not saying these are foreign trusts or PFICs --- just that the penalties for getting things wrong could be quite horrid, so you'll need to decide.
The extension date for the 3520-A (if due) is March 15th..