Submission of E-prints – Versioning
Here’s an interesting trend: the fraction of e-prints with mutliple versions has been increasing steadily in a number of categories. The figure below shows these trends for 4 major arXiv categories.

This figure shows the fraction of e-prints with mutiple versions for the arXiv categories astro-ph, cond-mat, hep-ph and nucl-th
I think that authors, over time, started to care more about replacing the initial version with the final version, or at least a more recent version (as some publishers still don’t allow the final version to be made available as e-print). Since the e-prints on arXiv are read so heavily, it is in the authors’ interest to replace their e-prints with corrected/updated versions. There are researchers in some disciplines who will only read and cite e-prints, maybe because their library cannot afford the subscription fees or maybe by choice, but it will be clearly beneficial to them if an e-print is a accurate representation of the end product. The Institute of Mathematical Statistics has the following standpoint with respect to e-printing IMS journal articles:
“IMS wishes to demonstrate by example that high quality journals supported by the academic community can provide adequate revenue to their publishers even if all of their content is placed on open access digital repository such as arXiv. A steady flow of IMS content into the PR (probability) section and the new ST (statistics) section of arXiv should help create an eprint culture in probability and statistics, and be of general benefit to these fields. By guaranteeing growth of these sections of arXiv, IMS will support the practice of authors self-archiving their papers by placing them on arXiv. This practice should put some bound on the prices of subscriptions to commercial journals.” (for more into, see IMS Journals on arXiv). They literally give their authors the following advice: “… when a final version is accepted by a journal, update your preprint to incorporate changes made in the refereeing process, so a post-refereed pre-press version of your article is also available on arXiv“. There are probably other journals and societies with the same standpoint.
We’re just seeing another symptom of the (necessary) paradigm shift in scholarly publishing.