It would be nice if the newsletter automatically provided a web-viewable version of a sent newsletter, both for archival purposes and so users without HTML capable clients can view the full version in their browser.

This feature should provide a macro to insert an automatic "View in browser" or similarly named link in the Newsletter 'page'. Maybe "{%ViewInBrowserLink%}".
The web viewable version should be automatically created from the actual newsletter HTML as well.
And/or maybe do a Newsletter document type that reads the specialized module data, sort of like products are done now?
(I know this can be done now manually, I just think it would be a good feature to be built into the Newsletter module.)