I believe that ITV Sport also use the GMTV gallery (and possibly studio).
CRT screens and GVG mixers which still work, still work! If they aren't unreliable (which they aren't on the whole if they are maintained well) then why replace them until you need to - for example to move to digital widescreen working. The pictures don't get better if the vision mixer is replaced with a new one (unless it is a move from analogue to digital - which it was in this case
) and programmes don't get better cos the PCs have flat screens instead of CRTs (though if they are used for long periods flat screens are better for operators' eyes)
As for London Studios - it does LOADS of shows! It is the home of London Weekend Television - so is the home of Blind Date and many other LWT studio shows. It is also used by independent companies - I think 'So Graham Norton' is made there. It is also used for 'This Morning' as well as lots of corporate events, and also LWT sitcoms etc.
I think it is quite a busy place!
LNN and LSN are also based there - so it is the home of London Today/Tonight and London Weekend Tonight (if that still exists) as well as local sports production.