As a result of the West Coast debacle between Virgin and First in October 2012, the franchising timetable was suspended until DfT came up with a more manageable plan. The new plan published in March 2013 requires GW to be refranchised in 2016, whereas the previous FGW franchise ran from April 2006 to October 2013 (having already been twice extended from March 2013 to July 2013 and then again to October 2013). The three year gap from 2013 to 2016 has been plugged by giving First a two-year extension from October 2013 to September 2015, but there will need to be a further extension or mini-franchise from 2015 into 2016. But by then all the plans may have changed again!
The two year extension includes only minor enhancements such as more seats on HSTs (by cramming them in or reducing first class), a longer sleeper train and more wi-fi. Other improvements such as doubling of the Kemble Branch and electrification are being carried out by Network Rail, with IEP and Crossrail to follow after 2017.
I did a lengthy analysis of the proposed new franchise, still available on the CRS website dated 9th August 2012, and an update on 13th March 2013, but the improvements proposed at that time may or may not be included in the next franchise, and in any case will not now take place until 2016, if at all.
You may also be interested in the Invitations to Tender for the combined Thameslink and Southern franchise and also for Essex Thameside (formerly c2c and LTS) published on 26th September (both new franchises to start September 2014), and the Prospectus for East Coast published on 25th October (new franchise to start February 2015). John.