To give you an impression what users want and what maybe qualifies to being in
Core, if it is FOSS :)
2004 LinuxQuestions.org Members Choice Award Winners Announced
Browser of the Year - Firefox (77.12%)
Distribution of the Year - Slackware (19.36%)
LiveCD Distribution of the Year - Knoppix (57.69%)
Database of the Year - MySQL (53.51%)
Desktop Environment of the Year - KDE (58.25%)
Window Manager of the Year - Fluxbox (31.14%)
Office Suite of the Year - OpenOffice.org (84.85%)
Word Processor of the Year - oowriter (63.75%)
Spreadsheet of the Year - oocalc (57.57%)
Audio Multimedia Application of the Year - XMMS (45.83%)
Video Multimedia Application of the Year - mplayer (49.85%)
Security App of the Year - nmap (37.14%)
Hardening App of the Year - SELinux (68.65%)
Editor of the Year - vi/vim (36.37%)
Web Development Editor of the Year - Quanta (50.88%)
IDE of the Year - Kdevelop (37.77%)
Mail Client of the Year - Thunderbird (47.60%)
Open Source Game of the Year - Frozen Bubble (25.52%)
Commercial Game of the Year - UT2004 (38.86%)
Windows on Linux App of the Year - Wine (42.59%)
File Manager of the Year - Konqueror (30.59%)
Messaging App of the Year - Gaim (56.00%)
Graphics App of the Year - GIMP (72.82%)
MTA of the Year - PostFix (45.57%)
From: http://www.linuxquestions.org/questions/t286716.html
See also http://www.linuxquestions.org/questions/f62 for details of each category.
Btw, Fedora is on number 2 of the distributions of choice.