Complying with the new EU Draft Communication from the Commission on the application of State aid rules to public service broadcasting [pdf] will pretty much obviate BBC Trust control over the market-based activity of the BBC:

Member States shall have appropriate mechanisms in place to prevent disproportionate market distortions and to control the market behaviour of public service broadcasters. Without prejudice to the enforcement of competition rules, such mechanisms should enable the control of eventual anti-competitive practices of public service broadcasters which are directly linked with the public funding they receive.

Third parties shall have the right to submit complaints concerning such alleged anti-competitive behaviour to an external body independent from the public service broadcaster. The supervisory body shall have the necessary powers to impose appropriate remedies and proportionate sanctions in case anti-competitive behaviour is demonstrated.