First Past the Post Loses
The key problem for large scale fibre upgrades in the UK is that the first company to raise the money and actually do it will never get a return on investment.
There are a couple of reasons behind this. Firstly the regulator would ensure 'competition' and force the operator to open the network to competitors. Secondly the government will step in and force the operators to reduce wholesale prices and therefore their wholesale prices to make the service accessible .
This is the reason why IMO all fixed line UK telecoms infrastructure (including the NTL kit) should be nationalised and operated by a single company  that is not allowed to operate any services on the network. Of course this will never happen...
 All this looks like is a slightly more permanant trial than the last few.
 Just like they did with broadband, which is largely responsible for the slow progress of ADSL2 (lack of investment funds).
 I wouldn't trust the government or the idiots at offcom to do so, so it would have to be a PLC which the uk.gov owns a controlling share.