The version of JLine that Roo has been using is 0.9.94. This is a Roo-wrapped jar and also has known issues such as the inability to backspace if the command line wraps to second and subsequent lines.
The new version, 1.0, is already OSGi enabled and fixes the known issues. Until it is hosted in Maven Central, the .0 jar will be hosted on the same server as the Roo-wrapped 0.9.94 version (/spring-roo-repository.springsource.org/release/jline/jline/1.0/).
See http://sourceforge.net/projects/jline/ for details about the new and improved features of JLine.