The vibrant competition between Evernote and OneNote is helping to accelerate the mainstream use of collaborative hypertext journaling tools, and both offerings will likely continue to evolve rapidly. Evernote secured an additional 20 million dollars in financing in October 2010, for example, and Microsoft continues to research opportunities for future OneNote-related possibilities such as the "infinite journal" concept embodied in Microsoft's Courier research project.
I believe that Microsoft's policy of supporting non-Windows device platforms with OneNote will be the most significant variable in terms of influencing the next phase of competition between OneNote and Evernote. If Microsoft delivers compelling OneNote clients for Android devices and Apple's Mac OS and iPad platforms, Evernote will lose a key competitive advantage. If I could use OneNote clients optimized for my iPad and Android phone, for example, I'd probably stop using Evernote, since it would be redundant with OneNote capabilities for my purposes.
On the other hand, Evernote's Trunk service and creative activities such as positioning Evernote as a migration destination for users of the once-popular social-bookmarking Delicious service (which Delicious parent Yahoo! announced plans to divest during December 2010) are clear indications that the Evernote team is finding interesting new applications for Evernote.