Hi and welcome to Just Answer!
The schedule K-1 should be provided on or before the Form 1041 is due (which is (March 7, 2011)
As long as you do not expect any additional TAXABLE income - I do not see any issues if you just go ahead and file your tax return.
If for any case you will get a schedule K-1 - and it will report either additional taxable income and/or deductions the trust passes on beneficiaries - you will be able to amend your tax return and claim those.
Let me know if you need any help or clarification.