I think its better to get a feel for the market and what news they really react to.
ft.com is a good place to start or marketwatch.com
Thursday / Friday were hugely interesting days, the dollar fell on Thursday meaning it became cheaper to buy oil, hence a rise up to $121 from around $116. Gold also rose from around $802 upto $836 i think..
So commodities has a good run as the dollar was cheaper, holders of other currencies were in a stronger position to buy these physical goods. Also you had the geopolitical tension with Russia fuelling oil and gold is seen as a bit of a safe haven when the equities start to teeter as they did from Monday on.
So what does this mean? the Dow is closely correlated to the price of oil however Thursday it didnt seem to pay much attention to the huge rise in oil! It had found some support around the 11380 area and come Friday the dollar started rising at 8.00 GMT when the pound fell sharply on the news you mention.
So the dollar becomes stronger, oil becomes cheaper, there was strong news from the financial sector (lehman takeover - which was bull, someone obviously paid reuters to make it up) so there was a strong base for a rally. The FTSE follows the dow fairly closely, a lot of bad news has already been priced in....
by the end of the day the dow was up to 11600 odd and oil had fallen back to $114 with gold at $822.
So what about the FTSE in all this? well the pound is cheaper so our exports will do well, the price of commodities had shot through the roof meaning our miners and oil companies were strong, we had strong news from the banking sector (lehman rumour, buy the rumour sell the news..) in america so that was strong. you can get a breakdown of the FTSE online from various places and you can work out if the various constiuents of the various sectors do well you can work out what the FTSE will roughly do.. think the top two are commodities then banking..
this is my take hope it helps...