Low hanging fruit (stuff that could be packaged right now):

2639 Home view needs to have an option to lock desktop applets into place
3455 telepathy-gabble deadlooping
3951 Incompatible quote handling in Busybox xargs (FEATURE_XARGS_SUPPORT_QUOTES disabled?)
3957 Busybox does not support "ls -Q" which some scripts need
3968 grep -r can output corrupt data in error message if file cannot be read
4079 busybox df does not handle root filesystem on command line
4119 digest-uri omits the serv-name part causing authentication failure when host != serv-name
4174 shell history file is overwritten after every command
4225 The x11vnc does not work on some areas of the screen
4803 Modest sends empty ENABLE command when IMAP server advertises ENABLE but not CONDSTORE or QRESYNC capabilities

Some stuff that needs more investigation:

2863 Allow setting of MTU per access point
3793 Segmentation fault when ossofilemanager access SMB shares
3885 RSS Reader Fails to Read HTTPS RSS Webpages
4248 Enable features in Busybox to increase its tools GNU/Debian compatibility