I would imagine this is akin to selling a PDF of an article or something
you've written, so I don't know that any license is required. If you've used
someone else's intellectual property in the presentation, though, then yes,
you'd need a license to use that.

http://office.microsoft.com/en-us/FX100829361033.aspx says, "You may
download, copy and use the templates in documents and projects that you
create. You may distribute those documents and projects non-commercially."
So I think, to be on the safe side, you will want to create your own
template or purchase one for your presentation.

If you purchase a template from somewhere, you'll want to check their terms
and licensing agreements.

Note: I am not a lawyer, so take this advice for what it's worth. If you're
concerned, you should speak with a lawyer.