The new Overground Network which was launched this earlier week only cover
stations and services on these routes:
Waterloo to Teddington via Wimbledon
Waterloo to Twickenham via Richmond
Victoria to East and West Croydon via Norbury
London Bridge to Dartford via Greenwich

Note: Even though half the trains on the Overground Network out of Waterloo
are actually the same trains, the stations and services along the route
between Twickenham and Teddington are NOT on the new Overground Network.

The idea behind it is, and I quote, "New pilot scheme promotes Metro rail
services for South London."

This was a pilot scheme known as South London Metro but has been marketed as
Overground Network. It is a pilot that covers 41 stations in South London.

I guess this is to justify TfL's new London Rail section
(http://www.tfl.gov.uk/rail/) which is in the same revolting brown colour as
the Overground Network.

So what does this actually mean? Well, Twickenham station has been
refurbished(It took over a year to complete.) It now has a nice new shiny
station front, a new National Rail very tall totem pole, a little bit of
painting, a lift for wheelchair users for platforms 4 and 5 but not 1 and 2.
This week there was the appearance of an Overground Network poster site
outside the station and line diagrams at the top of the staircase for
platforms 4 and 5 just like you see at tube stations.

"All 41 stations on the Overground Network meet the ON standards:
o Frequency - minimum of four trains per hour during daytime off-peak
(Monday to Saturday)
o Passenger information - investment has been made to install distinctive
new station signs and better information points, which include clearer route
and network maps, better frequency information and details of connections to
other modes of public transport
o Security - CCTV coverage and help points.

Additional evening services, funded by TfL London Rail are also being
piloted between London Bridge and Dartford, increasing frequency on Mondays
to Fridays from two to four trains per hour until 10pm."

In terms of train services, well it's exactly the same as before. There's
usually long gaps between trains going to Waterloo. There's no evening
service between Hounslow and Twickenham. There's only a half hourly service
between Twickenham and Teddington. That's why these services along with the
rest of South London are not on the Overground Network. At this stage it's
just a pilot project to encourage those that don't use rail off peak to try
a "metro" style service.