The conference is Thursday and Friday. First up on Wednesday is a NISO sponsored workshop about setting standards and best practices for altmetrics. For that workshop I'm giving a "lightning talk" (5 minutes) about the need for data sets and visualizations to be of equal standing with journal articles and monographs.
This nomenclature confusion--is it article-level metrics or altmetrics?--is telling. "Article-level" privileges the scholarly article, as per tradition, but goes far beyond the impact factor in understanding an article's influence. "Altmetrics" defines what counts as scholarship more broadly, welcoming those aforementioned data sets and visualizations into the fold while still admiring the journal article. Within this larger family the need to measure impact--but not the impact factor--remains the goal.
So I'm a partisan of "altmetrics"--it's a more inclusive term, with room to grow as we broaden our understanding of digital scholarship. Article-level will confine us to the textual track.
Perhaps this is much ado about nothing; after all, a rose by any other name does smell as sweet. By the end of the week, I'll have a better sense of whether this is a fundamental semantic difference or just two different ways to say the same thing. I'll be tweeting this evolving understanding @mab992 and will offer a full wrap-up of the conference next week.