What a great set of questions! Thanks to everyone who enjoyed my article. I'll try to answer your questions here.
jcrawf02, The intent of this article series is to be an introduction to Reporting Services. I consider those to be more advanced topics, so wasn't planning on including them. I'll see if I can fit multivalue parameters into a later article though! In the meantime, here is a good reference on using the Lookup function: http://prologika.com/CS/blogs/blog/archive/2009/08/12/reporting-services-lookup-functions.aspx
sbramblet, The result of working during the day and writing during the evening
I will do my best to get the rest of the series out as soon as I can!
Ninja's_RGR'us, I'm actually not familiar with iPhone development, but SSRS reports can be exposed through any web browser. You may want to check out the mobile chapter in this book for help: http://search.barnesandnoble.com/Professional-SQL-Server-2005-Reporting-Services/Paul-Turley/e/9780764584978
Joe Fuller, Sure thing.
1) Yes, you'll want the .NET Teradata provider, which you can find here: http://www.teradata.com/DownloadCenter/Forum146-1.aspx
2) The "SQL or sproc" debate has been debated almost religiously over time, but my view is that it makes sense from an SSRS perspective to use stored procedures
kpatrick, The best way to merge data from different datasets into one report item is to use the Lookup function (introduced in 2008R2). Be aware that it doesn't scale very well, so you'll need to use it with caution. I won't be covering it in later articles, but hopefully this will help you!
And I'm off to work on the next article - thanks all!