Transport for London is likely to gain control of suburban rail services currently operated by First Great Western and the National Express One franchise when the London Crossrail project is completed - scheduled for 2017 (link below.)
http://www.rmtbristol.org.uk/2007/12/crossrail_toc_set_to_swallow_o.html#more

The Crossrail TOC would take over the operation of certain existing services currently running out of London Paddington and Liverpool Street stations , to Maidenhead and Shenfield respectively , when the FGW and One franchise agreements end. The new TOC would receive revenues for the routes assumed and would also inherit the 'operator of last resort' obligations that accompany the services.