In SQL2000 I had a project where we had to execute DTS packages from clients that didn't have SQL Server installed. For that project I did create a sp that would execute the DTS package. It made calls to spOACreate and others but you can call them in the correct context to avoid security issues.

I just saw this posted today (I am not the author, indicating a method to do the same w/SSIS. I have not tested it but thought it should be posted for review in case anyone can use it.