If this is a game of poker, have we shown our hand too early

Tuning in to the Today programme this morning I learned that the Government had announced its latest rescue package for UK banks.
The Government is going to make £50b available for banks to access if they require funds to shore up their capital. This is likely to be in the form of preference shares. The first question is where is the cash coming from if as we are being told constantly, the government has no available cash. Presumably it is borrowing this from the market place, that same market place that won't lend to other banks.
Secondly, what is the upside here for the British taxpayer? Bank shares are at a ten year low. Presumably over the medium term, with the guarantee of government support and a pledge that "we will do all that is necessary" these bank shares will rise considerably in value. Is the British tax payer getting the type of share that can be sold in due course and the benefit of the increase in share price realised?
The second element of the rescue is that the government looks like it is going to provide a guarantee for a bank which has to the market to replace it's short term borrowing used to fund its long term mortgage lending. eg HBOS may need to replace £100b of this type of funding in the next three years or so. If the money market will not replace this borrowing the government intends to act as guarantor for the banks ability to meet any repayments on this money, and to bolster the security given to secure it. Again, any shortfall on the security will be picked up by the British taxpayer!
My question this morning is whether the market will see fit to accept this latest offer. The government and the Bank of England have been intervening for months now by providing cash for liquidity, to little effect. This is a bigger plunge, and is significant, but the market is not driven by sentiment. My worry is that the market will effectively say, "Thanks British Government, that is a nice offer, but we think that you can go higher". Essentially they will play a game of poker and see just how far they can push not only our government but others around the world. If I am right and this is like poker, have we revealed our hand too early, and what else have we got to offer. Actually shouldn't we be calling the markets bluff and saying, that's it. Take it or leave it, there is no more.