I expect there will be many reviews and wish lists for R this year, with many of them focusing on either running speed or dealing with large data sets. However, most issues that I would like to see tackled in R next year are not technical but, for lack of a better word, social.
Many users will first encounter R through the r-project.org website. This site is begging for a redesign, which could start getting rid of the frames (which have sucked since a long time ago). At a minimum, this would make pages much easier to bookmark.