The KDE4 version of kaffeine in Fedora 12 repos, kaffeine-126.96.36.199.pre2.fc12, looks like a testing version. It misses basics like deinterlacing and aspect ratios for digital tv and minimal mode which make it not even usable for me.
DVB playback in kaffeine is very popular, and I really think the kde3 version of kaffeine should be made available in the repos as an alternative for the time being.
If that isn't possible, then in any case you can manually download the kde3 Fedora 11 version from a mirror
and install using yum, it resolves all dependencies, and only brings in 4 extra packages (~18mb, including kdelibs3)
yum install --nogpgcheck kaffeine-0.8.7-7.fc11.x86_64
(At first I got DCOP errors running this kaffeine until I disabled selinux and rebooted, but that may just be my system, since I've tinkered with it a lot)
EDIT: For Standard Definition DVB in the UK I find the best deinterlace setting (ctrl + i) in kaffeine is (surprisingly) the second one, "Low cpu usage, poor quality", since the vertical blurring helps remove the pixellation artifacts in SD, especially on larger screens (Just like the blurring effect on CRT displays gives what many consider a better image than LCD tvs for SD)