JPM's valuation represents a historic earnings multiple of about 30. With other stocks in the transport sector averaging a p/e of 15-20, I find it hard to take a £10b price tag seriously, especially with the strategic challenges the business faces going forward.
The particular size of the business has created its own issues - being just above the threshold of FTSE membership at its present share price means that every FTSE tracker fund in the world has to have a piece of it. It's my feeling that, although 330p might turn out to be on the low side, better that way than to have priced it at £5+ and seen it flop.
JPM are merely displaying pique that they didn't land the deal. If they had, it would have flopped but they would still have had their fees.
The final proof will not be available until the Government's remaining 48% stake is sold.
And here's an example of JPM's recent track record in getting markets right.
http://dealbook.nytimes.com/2012/06/28/jpmorgan-trading-loss-may-reach-9-billion/?_r=0
Getting JPM to value your company is like getting a burglar to value your jewellery.