Just been announced that the government is to give Ken authority over
all railways "within the GLA area".

See
http://news.bbc.co.uk/1/hi/uk/3894791.stm

Does this mean that the mutterings about zones 7, 8 and 9 might go ahead?

Possibly, but remember that the boundary of zone 6 is in almost all
cases coterminous with the boundary of the GLA area. (i.e. 'Greater
London' or the 33 London Boroughs) Indeed, if zone 7 comes into
existence, Buckhurst Hill-Epping, Roding Valley-Grange Hill and Thames
Ditton-Hampton Court might well be moved into it. (Are there any other
places within Zone 6 but outside Greater London?)

Yes. Stoneleigh station is in Ewell, Surrey (but only just). It's
probably why it's in zone 6 rather than 4 or 5. It also makes it look
slightly less obvious that the GLC boundary suddenly zig-zags in and
out by about 3 miles at that point (and is consequently very silly and
rather inconvenient).

Really, the whole issue of zones shows up how the GLC boundary is in
the wrong place. There are two approaches I would like to see - either
that Epsom & Ewell and Reigate & Banstead get pushed into Greater
London, or that Kingston and Richmond are moved back into Surrey
(which would at least have the useful function of moving the centre of
gravity of the county away from Guildford), forcing co-operation
across borders.