The following thoughts are from a media business perspective. I LOVE Fox News and this is in no way a criticism of the network or the new line-up. Just thoughts I have concerning the networks from a business mindset. I wish Fox News all the best with the new lineup and in the future!
If CNN was smart, they'd hire a conservative to do a show at 8pm to give former faithful Bill O'Reilly viewers that may be looking for alternatives to Fox an option. Maybe Mike Huckabee, Laura Ingraham, or some other traditionally conservative personality a show that could steal some Fox viewers that aren't maybe interested in Tucker Carlson. Move Anderson Cooper to 9.
MSNBC should move Rachel Maddow to 8 since she's their biggest (Only?) draw to go head to head with Fox at 8. Or, leave her at 9 and continue to close the ratings gap at that hour since she's been gaining ground there.
Glenn Beck should advertise TheBlaze to disenchanted conservatives that aren't excited about the Fox changes and welcome them to his network. Set it up as a conservative alternative to Fox.
Fox News should run a huge advertisement/PR campaign to let their viewers know that Fox News is still "Fair & Balance" and still "The voice they can trust" to ease any core viewer tension about the new lineup or where the channel is heading.
And there is always A Whittle Bit of Commentary for you if none of the above networks interest you!