Quick note. Doug Laudenschlager (I've checked and rechecked the spelling - I think that's right :) from the SSIS team has begun a SSIS related blog at Dougbert.com (RSS feed). Doug is the technical writer on the team which means that he writes all the SSIS documentation in SQL Server Books Online. Hence, what Doug doesn't know about SSIS really isn't worth knowing. His personal introduction is here.
I happen to know that Doug is working on an addin for SSIS that many people have asked for and I expect he will announce its availability on his blog pretty soon. (Hint: If you consume data from Excel workbooks with multiple worksheets then you will want to pay attention).
For starters, check out his post on the MULTIFILE Connection Manager The Mystery of Multifile (which I was wrong about. Whoops.)