1 not important at all
2 least important
3 medium important
4 important
5 most important
More social media "share" buttons underneath each article
Ability to comment on / discuss each article on each article page
Article level impact metrics (citations, views, tweets) on each article page
Nicer table of contents with images / thumbnails for each article
Classified ads on the site (jobs, conferences)
Interviews (audio/video) with authors for each (or specific) articles, podcasts
iOS (ipad/iphone) or android app
Download entire bibliography of each article into bibliographic software (Endnote etc)
Collections of articles with specific topics (Topical e-collections)
Profile pages of authors, users etc with social networking capability
Wiki pages associated with each article
Database of ongoing ehealth research and protocols
Web-app mode (web content optimized for mobile devices)
Newsarticles, Industry news
Journal Club (discussing papers published elsewhere)
More commentary and editorials
Readers can rate each article (e.g. 5-star scale)