Hi Andres,
As long as you're getting direct followed links back to your original article, then that should be enough. A couple of other things though:
- Even though you're confident you'll be indexed before the other site, I'd still implement some embargo time on when they can publish on their site as a fallback.
- Take a look at the site itself that will be linking to you... is it something you a) want your content associated with, and b) want your link profile associated with?
Some resources you may be interested in:
[1] http://www.seomoz.org/blog/whiteboard-friday-content-technology-licensing
[2] http://googlewebmastercentral.blogspot.com/2006/12/deftly-dealing-with-duplicate-content.html (deals with syndication)
[3] http://www.mattcutts.com/blog/duplicate-content-question/