As there is already for +1.
Also I expect the news will be replaced by a caption as mentioned above. I wonder if the 2 minute bulletins will feature promos instead to save people thinking the show they're tuning into can't be shown.
I doubt it will literally be Channel5+24. It will be it's own channel with it's own presentation and, most important of all, it's own adverts.
5Later is to Channel 5 as 4seven is to Channel 4.